Relating Trends in Streamflow to Anthropogenic Influences: a Case Study of Himayat Sagar Catchment, India

Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Sciences Discussions Earth System Hydrology and . The main land use change was 1 − . Surface water storage capacity for regression model was used to quan- 1 ff − relationship over the study period. Then, ff , typical irrigation practices suggests applied 9296 9295 1 − , while estimates of evapotranspirations using AVHRR 1 − This discussion paper is/has been under review for the journal Hydrology and Earth System Sciences (HESS). Please refer to the corresponding final paper in HESS if available. severe in the future (Rockstromshortages et in al., regions 2009). and A river range basins of including studies the have discussed Indus, water Ganges and Krishna basins images showed an increasingvarious rate small of watershed 4.1 mm development yr gether, structures the increased streamflow trends 2 mm andestimates over groundwater of information 7 yr. evapotranspiration suggest changes Taken the comes to- most from plausible the AVHRR imagery. 1 Introduction Many regions of the world face water shortages that are increasing and may become monsoon (Kharif) season (June–November)during and the from dry 8evapotranspiration/irrigation % (Rabi) water to season use 16 % (December–March). werewater of made. Various extractions increase Well cropping estimates of inventories area of 7.2water suggest mm increased yr changes ground- by 10.8 in mm yr Himayat Sagar catchment. A simple rainfall-runo tify the change in magnitudethe of anthropogenic rainfall-runo changes inment, the groundwater abstractions catchment and including storages,The land and evapotranspiration changes use, were watershed in quantified. develop- theflows components were of found the tofound water decline to balance at be were a a then ratetractions. conversion compared. of Irrigated from Stream- 3.6 mm rainfed area yr to increased irrigated from agriculture, 8 fed % by to groundwater 23 % ex- of the cropping area during the Catchment development has beenstreamflow identified in as India. potentially This causingSagar paper major catchment and tests changes shows for in majorin trends declines precipitation. in in It rainfall streamflow without and then significant streamflow relates changes in the Himayat streamflow trends to anthropogenic influences in Abstract Hydrol. Earth Syst. Sci. Discuss.,www.hydrol-earth-syst-sci-discuss.net/9/9295/2012/ 9, 9295–9336, 2012 doi:10.5194/hessd-9-9295-2012 © Author(s) 2012. CC Attribution 3.0 License. Relating trends in streamflow to anthropogenic influences: a case study of Himayat Sagar catchment, India R. Nune, B. A. George, P. Teluguntla, andDepartment A. of W. Infrastructure Western Engineering, The University of Melbourne,Received: Melbourne, 25 Australia June 2012 – Accepted: 2Correspondence August to: 2012 R. – Nune Published: ([email protected]) 9 August 2012 Published by Copernicus Publications on behalf of the European Geosciences Union. 5 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ect the downstream ff ects on base flow trends. Most of ff erent drivers that impact water resources ff 9298 9297 ciency of artificial tanks found that only 35 % ffi ecting the local climate (Cassardo and Jones, 2011). ff ect water availability, in particular streamflow and groundwa- ff in the upper Merguellil catchment is due to consequences of ff ects on streamflow and groundwater availability that may lead ff ected by droughts (World Bank, 2005). Therefore, Water Develop- ff While these structures are beneficial to upstream users, they a This study aims to understand a variety of changes in the Himayat Sagar catchment The most visible sign of hydrologic change in a catchment is from the trend of stream- The drivers that could a total volume every year to evaporation due to their high surface area to volume ratio water for use duringgion. dry This periods. region is The historicallybeen study among severely area the a (HSC) poorest is areasment Structures in located (WDS, India in Fig. and 1) a it suchdams, semi-arid as has sunken percolation previously re- pits, tanks, and mini-percolation farm tanks, pits, check have been developed inflows. the A study area case-study (HSC). onof percolation stored e water rechargessmall water the storage groundwater structures (Sylvain reported et that al., these 2008). structures Another can study lose on 50 % of their grammes have intensified after the launchaspects, of finance, detailed training new and guidelinestion, on stakeholder 2001; organizational participation Hanumantha (Kalpataru Rao, 2006). Research Inprogrammes Founda- many aimed arid and to semi-arid improve regionstural socio of production India, economic in these conditions rain through fed increased areas, agricul- and to control land degradation by conserving rain- streamflows to all the changes within the catchment. (HSC), India where thereincreased hydrological has structures been and ascale groundwater up. extractions number Since that of 1987, are in changesvelopments challenging drought to under at prone various small areas of watershed scalesthe India, Government development including small of programmes scale India, were waterIntegrated including resource Wasteland introduced de- Development the by Programme Drought (IWDP). Prone From 1994–1995, Area these Programme pro- (DPAP) and crease in surface runo human activities. Similarly Vanclimatic Kirk (irrigation withdrawals) and drivers Namanthe and (2008), studies their have analysed a discussed climaticclimate streamflow variability and trends or non- with both respect within to a catchment; changes whereas in only land a use few or studies have related distribution and land use changes. In Tunisia, Chulli et al. (2011) , found that the de- trend in the upper Gilgel Abbay catchment and found it to be associated with rainfall flow, which indicates thatdoes changes not provide have information occurred onSuch the within relative information the contributions of is catchment multiplechanges critical but, drivers of into in for change. the itself, developing evidence future.in based A streamflow with policies number respect of tothropogenic to activities. studies manage For changes have such e.g. in triedstreamflows Adnan climate, to of and catchment the Atkinson explain (2011) Kelantan characteristics observedtion catchment, observed and trends and Malaysia that an- resulted the land from trend use in changes in in the precipita- catchment. Rientjes et al. (2011) evaluated the streamflow While development activities may providealso benefits have in adverse agricultural e production,to they both can human and ecologicaldeveloping catchments, impacts there downstream are (Schreider often a etwith number significant al., of potential 2002). changes to In occurring impact rapidly simultaneously on the hydrology. ter include climate change, waterscales, and resource a development wide and range watercific of use anthropogenic examples at changes include a in construction catchment varietyRamireddygari characteristics. of of et Spe- water al., 2000; retention Schreider structurestural et al., (Beavis land 2002) et use , (Masih al., increased and/orwater et 1997; storages changing al., for agricul- groundwater 2011) recharge and (Ramireddygari2007). et increased al., In groundwater 2000; some Alemayehu extraction cases, et these and al., variationsenergy artificial may balance, change evapotranspiration thereby and also the surface a ropean countries (Stahl et2011) al., and 2010) in Australia , (Chiew many andphasised McMahon, regions the 2002) in , necessity among England of others. (Charltonfor These understanding addressing studies and di em- future Arnell, water shortages. in south Asia (Bouwer et al., 2006; Sharma et al., 2010) , southern and eastern Eu- 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ff , of which 1 − temporarily, which passes ff C during summer and a minimum ◦ 70 % of catchment area), along with > 9300 9299 and is an upper part of the Musi River catchment, 2 . In 1927, the Himayat Sagar reservoir was constructed on permanently in the catchment. permanently in the stream bed. Therefore, the main runo 2 ff − ff C during winter (George et al., 2007). ◦ In this study, the term watershed development structures implies particular struc- The main stream in the HSC is the Esa River, which has a dendritic stream net- The average annual rainfall observed in the catchment is 718 mm yr This paper examines these issues in the HSC, which has undergone a suite of tions distributed in andStatistics around the (DES); study HS area reservoir from the data Directorate from of the Economics and Hyderabad Metropolitan Water Supply 3 Data The data used inment departments this in study Andhra was Pradesh,sensing India; collected images field from survey; on three andused Google interpretation sources: and of Earth. the remote are The relevant describedin Govern- following in the sources more methods of detail section. Government in Data data this collected section, were included: with daily the rainfall other data data of described 12 rainfall sta- structures is erosion control, thoughdownstream slowly. they The store sunken some pits runo andtures, feeder but channels are they also hold siltcapturing runo controlling struc- structures arefarm percolation pits, which tanks, hold mini-percolation runo tanks, check dams and work of density 0.4 km km Esa River near the catchmentfloods outlet and and supply drinking 9.6 km water upstream to(HS) the of reservoir city. Hyderabad The and city Esa then River to joins flows control the into Musi the Himayat River Sagar downstream oftures which the play reservoir. an importanting role in percolation improving local tanks, access mini-percolationstructures, to water tanks, feeder resources, check includ- channels dams, and sunken farm pits, pits/ponds. gully The control main purpose of gully control by mid October. Theremonsoon season are (June–November) two and mainAgricultural the lands crop Rabi are kept or seasons fallow dry duringfor in the the season this summer next (December–March). season Kharif catchment, (April–May) season. in the preparation Kharif or typically starts by early June, gradually recedes from early September and finishes nearly 90 % occurs in the south-west monsoon season (June–October). The monsoon tricts of the state(13 of %) Andhra as Pradesh, shown namelyand Rangareddy in 217 (87 villages Fig. %) either and 2. partially Mahabubnagar from There or 527 fully are m covered by 12 to the3 726 Mandals catchment. % m The slope. (a above elevation The varies combination sea soilsloamy of level are and with predominantly a rock clayey flat few ( formations villages) topographyThe extreme making ranging temperature up reaches between a the 1 maximumof % of remainder 12 and 44 (Gurunadha Rao et al., 2007). 2 Study catchment The HSC has anwithin area the of Krishna 1340 km River Basin in Southern India. The catchment partly covers two dis- changes due to watershedited declining development streamflows. over The the paperflow first past trends addresses two the are decades questioncatchment) exogenous of and by (climate whether characterising has stream- forced) the exhib- changes trends or in in endogenous catchment climate (due characteristics andit due streamflows. to compares It to the changes then anthropogenic changes examines in activities withthe in the trend the aim detail. in of streamflow. Finally investigating which drivers could best explain utilisation has expanded andsemi-arid it areas. has Overall, the become usecurrently a of in conjunctive water resources resource India for for(Benoit 78 irrigation % agriculture et has in of accelerated al., and irrigated 2007).reductions in Coinciding land downstream with is flows (Schreider all supplied et these al., through 2002). changes, groundwater there resources have been significant (Sakthivadivel et al., 1997). Due to rapid development of these structures, groundwater 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | 75 %). < 9302 9301 erence between the net sown area and the irrigated area ff 100 %), Critical (90–100 %), Semi-Critical (75–90 %) and Safe ( > trol (sunken pits, feeder channels and(check gully dams, control percolation structures) tanks, or mini-percolation groundwater recharge tanks and farm pits). Although the silt per hectare used duringrepresentative the villages cropping of seasons, every were category. collected through field3.6 survey in Watershed development structures The information of watershedtracted development from structures the data (1995–2005, collectedcations Table at covered 3) within DWMA, the was Rangareddy catchment. district ex- The based function of on these the structures village is lo- either silt con- Exploited ( The groundwater status hastwo been years. The evaluated groundwater in status (2004–2005)villages every was within watershed taken as the by the watershed CGWB average (Fig. statuswater for 3). for extractions all The every including information typical needed pumping to hours estimate and the ground- flow rates, the number of wells Water Resources), India. The numberobtained of from groundwater the wells district withindistrict. the level catchment information was and the percent of3.5 area covered by Groundwater extractions each survey The groundwater extraction surveytus has in been the taken catchment. placeon The based on groundwater the status groundwater ratio sta- is defined of using groundwater four categories usage based to rainfall recharge. The categories are Over- The locations and other detailsrespectively. of The the surface observation elevations wells of arefrom given observation in 570 wells m Fig. above 2 to mean andmation 680 Table sea m. 2, (1980–2004) level The was range obtained district from wise the groundwater Minor production Irrigation wells Census, (MIC, inventory Ministry infor- of 3.4 Groundwater levels groundwater sources. The di was considered as rain fed area. 3.3 Land use information The mandal (sub-district area,(1985–2004) 1985–1987, wise 1991–1994 land andData use gaps 1999–2004) (1988 information and and of 1990) district foundpercentage the in changes the observed study mandal in level area were the filledKharif district was with level (monsoon, the information. collected corresponding June–November) Area and from irrigatedcatchment during Rabi DES. were the (dry, obtained December–March) from the seasons mandal in wise the information under area irrigated by the Monthly streamflow into HS(1980 reservoir to 2004), has storage-area-capacity been tables, surplus estimatedter discharges supply using (1980–2004) withdrawals and (1980 water wa- to storage 2004).evaporation levels Evaporation depths losses are estimated estimated by usingthe HMWSSB monthly years and during were the assumed study period. to be constant for all 3.1 Rainfall The 12 rainfall stations and theirties locations are are shown given in Fig. in 2, Tableabove and 1. their sea The detailed level. elevation proper- of Amongwhile rainfall these stations the stations, other ranges six six from had 535 had m shorter longer to records records 720 covering m 3.2 1990–2004. covering 1980–2004, Reservoir data nomics and Statistics (DES); Groundwater levelsmonsoon (pre-monsoon (end (end of of May) November)) andBoard post- of (CGWB); 10 and observation thethe wells time District series from Water of the Management WDSs Agency Central (DWMA), sanctioned Groundwater Rangareddy in district. Rangareddy district from and Sewerage Board (HMWSSB); Land use statistics from the Directorate of Eco- 5 5 25 20 15 10 25 20 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | (2) (1) empirical b and a were then summed to the evaporation volume i R E , into HS reservoir for the i model (Eq. 2) to simulate is a rainfall threshold below R t ff P RS is the change in reservoir storage ∆ response and 9304 9303 is the annual rainfall (mm), ff from the catchment. The area-volume relation- depth (mm) by dividing by catchment area. P ff ff t t P ≥ i P < P P D ) is the time period (month), t + P i i − E is the water supply withdrawal volume (GL), P + ) into the reservoir: i 0 )( W R erent annual rainfall percentiles. W b is the discharge/spill volume (GL) from the reservoir. Negative streamflow ff + + i D is time (years since 1980), at t ( RS data in the HSC and then quantifying the change in streamflow over the study ff = ∆ First, we fitted a non-linear regression rainfall-runo Streamflow is not directly observed in HSC; instead it was estimated by applying a = ¯ i Where parameters for the trend in rainfall-runo This analysis involved fitting and evaluatingruno a regression model to observed rainfallperiod and for di streamflows ( R from the TREND tooltrends in (Chiew the and time Siriwardena, series(1980–2004). data 2005) A of 5 were the % used annual significance streamflow level for was and detecting adopted rainfall during for linear 4.3 this study test. period Quantification of change in magnitude of streamflows In Eq. (1), subscript volume (GL), (GL) and estimates during the non-monsoonannual period values were and set converted to to runo zero. 4.2 Estimating trends of streamflow andNon-parametric rainfall trend analysis tests (the Mann-Kendall test and Spearman’s Rho test) water balance to thestudy HS period reservoir. were Monthly then streamflows, estimated using Eq. (1). R stations with long records. 4.1 Estimating streamflows and catchment averageThe rainfall consistency of rainfall recordsAreally was weighted checked using average the annual double rainfallgon mass was method curve then method. (ArcGIS) estimated using usingthe the 12 rainfall Thiessen rainfall data poly- stations. (estimated Inmated addition from for to the the this, whole available study weighted period annual records) (1980–2004) catchment from using rainfall continuous was data esti- from the 6 rainfall First, we examined theSecond, streamflow we and quantified rainfall the datacompared variations for the in statistically trend streamflows significant inplace over trends. streamflow during the to study study various period. period. anthropogenicand Before Third, streamflow changes discussing we data that each preparation have of procedures. taken these steps we describe rainfall Sat images taken during the monsoon seasons of the years 1985, 19894 and 2002. Methods This section describes the studytrend, conceptualization, estimation and of analysis streamflows and of their include anthropogenic changes in changes. land In use, groundwaterdevelopment this extractions structures. paper, and The water anthropogenic analysis retention changes presented in in watershed this section consists of three parts. could capture iscapture relatively a small. significant There amountships of are of runo fewer each recharge typeApart structures of from structures but these were they watershedthe collected can development catchment. during The structures, surface field tanks areas work are of and these existed tanks are historically were in in obtained Table by 4. analysing the Land control structures occupy a major part in total number, the volume of water that they 5 5 20 15 10 20 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | (5) (4) (3) values using the recharge relationship at ff ff chg R must be balanced by ff erent annual rainfall percentiles. ff were obtained by minimising the t P ) to the catchment equals the sum P ) from the catchment plus the change and R b , a 9306 9305 is the number of grid cell, j the average of change in water head (mm, post H ∆ , within the catchment. Equation (3) is applied for the S ∆ , and streamflow, E 1997 H − are used throughout. ) occurs. The parameters t N 1 ( i ff − R t H H + 1 ∆ the specific yield and E = y is the time period (annual), n j y S + t P S = S t = t erent time steps (1980, 1990, 2000 and 2004) for di Third, the change in interception due to watershed development structures over the Second, changes in groundwater storages were obtained and their trends were anal- First, land use was classified into four classes namely forest, range land (which in- The hydrologic components in the HSC was conceptualised using a simple mass Second, we quantified the variations in magnitude of rainfall-runo = ∆ ff H chg, R ∆ in the missing area (13tures, % the of small structures study such area) as of farm the pits are catchment. often Among constructed the by retention individual farmers struc- groundwater head of the catchment.heads For for this, each the grid pregroundwater cell and heads post was and monsoon obtained elevations groundwater The by at groundwater applying 11 heads the of observation correlationto 1997 wells between evaluate (pre the every observed and change year in postThen, (1997–2004). heads the monsoon) mean of were heads remaining considered of periodson. all as (1998–2004) grid The datum as cells average was given of considered ingroundwater as pre Eq. storage the of (5). and average the head post year. of monsoon the sea- heads was taken as average change in Where (mm), monsoon and pre monsoon). study period was estimatedpits/pond, as follows. check The dams, inventoryDWMA of percolation data. water and retention As such the mini-percolationRanga as data tanks reddy farm collected district), were from Google captured DWMA Earth covers from images 87 % were of used to the count study the area major (only structures very low (10 % of average annual rainfall). ysed. The change inmonsoon groundwater storage groundwater was heads estimatedgiven using and in average using pre Eq. Water and (4). post Table The Fluctuation Digital (WTF) Elevation Model method (DEM) as was used to obtain the average using groundwater during the Rabi season, as the rainfall contribution in this season is resource usage, the netrainfed sown area. area Area (first sown more crop) than was once partitioned was into assumed to irrigated be area the and second crop irrigated trends in one or more of the otherP components. Units of mm yr cludes barren lands, non-agriculturallands use lands, and pasture other lands, fallow trees,Then, lands), cultivable to current waste examine fallow the land detailed and changes net sown in (i.e. land first use crop) associated areas. with significant water of outputs (evaporation, in (groundwater) storage, period 1998–2004 as the dataavailable. required It to is evaluate assumed the thatthis changes period. in changes all This in components equation unsaturated are implies zone that storage a are trend negligible observed over in runo 4.4 Analysing anthropogenic changes In this section, we address threeotranspiration; aspects groundwater of storage anthropogenic and change: extraction; landcal use and structures. and These interception evap- changes due can to influenceentire the hydrologi- catchment hydrological water components balance. and alter the balance method (Eq. 3). That is, input (rainfall, sum of squared errorsMicrosoft Excel between solver. observed The andpredicted model values. simulated quality annual was evaluated runo by plotting residuals against di which no runo 5 5 15 10 20 25 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | 1 − 0.02, − (1983), = 1 − a . It is observed for these years 1 ff − data (1980–2004), respectively for the ff 1 − and it ranges between 1 − (2004) and 247 mm yr 1 − cient of variation of 1.04. The 5-yr ffi was 0.76. Figure 5b shows the model 2 R and coe 9308 9307 1 − (1983) with a standard deviation of 153 mm yr 1 in 1980. Using these parameters, the model for 1 = − t cient has declined from 14 % (1980–1984) to less than 5 % ffi , ranging between 2 mm yr 1 coe − ff cient of determination, ffi 518 mm, where = t P (2004) and 996 mm yr 1 − cient of variation of 0.21. The trend tests performed on two sets (1980–2004, ffi 0.47 and = pogenic activities. First, wethe examined groundwater the levels and changes groundwater in draft; land and third, use; we second examined the we trend examined in time to 2004, the predicted streamflows25th, declined 50th by and 27, 75th rainfall 61 percentiles. andin The 113 median streamflow mm change during respectively (i.e. the for 50th study the rainfall percentile) period is a 765.3 % reduction, from 1980 Characterizing to drivers of 2004. streamflow change In this section,tics we that first could characterise influence streamflows. the These changes are in endogenous changes various due catchment to characteris- anthro- for which the coe residuals plotted over predictedthe data. values, It which is indicated observedb that that the the parameters model resulting1980, from fitted 1990, the well 2000 model to fit andand are 2004 the is 25th, shown 50th in and Fig. 75th 5c. percentile The annual rainfall predicted are runo given in Table 6. From 1980 while no trend was observed inThis rainfall over strongly the suggests study period, that at(i.e. observed a internal 5 changes % to significance in the level. changes streamflow catchment, in anthropogenic) are the rather due catchment. than to exogenous endogenous (due to climate) 5.2 Quantification of change in magnitudeFigure of 5a streamflows shows the model (Eq. 2) fit to the annual rainfall-runo and 2000–2004 were declinedcorresponding as average 105, rainfall 55, of 50, 735,that 46 the 715, and average runo 705, 32 mm 748 yr (2000–2004). and Also 687 the mm yr trend testwere on declined annual significantly streamflows (Table 5). suggests Overall, the that streamflows the showed streamflows a declining trend, average streamflows for the periods 1980–1984, 1985–1989, 1990–1994, 1995–1999 estimated as 58 mm yr with a standard deviation of 60 mm yr Figure 4 showsweighted the average pattern annual of rainfall471 is annual mm yr estimated average as rainfall 718and during mm yr coe the study6 period. rainfall stations; The 1990–2004, 12 rainfallshows stations) no of significant catchment average temporal annualreservoir trend rainfall is (Table also 5). shown The in Fig. annual 4. streamflow The average pattern annual streamflow into into HS the HS reservoir is In this section, wewe firstly quantify test the the temporal changespacted trends in the in streamflows streamflows rainfall before in and the we streamflow. HSC. examine Secondly, the drivers5.1 that have im- Estimation of trends in rainfall and streamflow late the information for the entirewere catchment. estimated The by surface classifying area Land ofing Sat already the images existing tanks for ERDAS the Imagine yearsinterceptions software 1985, by (Chander 1989 these and et structures 2002 was al.,field us- estimated data 2009). based and Overall, on extrapolated the the data. data total collected volume (DWMA), of 5 Results capture this information we randomlymapped selected the 25 structures villages using inwere the Google grouped entire as Earth catchment per images. and groundwaterarea The and status mean the of means densities the of village,significance of these among total farm groups them. village were The pits area compared best correlation and using was ANOVA irrigated test taken into to consideration analyse to the extrapo- with no Government funding and these are missing from the information collected. To 5 5 25 15 20 10 25 20 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | 1 − and 1 − for dry (assum- 1 − 1 (2004) per − (2004), and 1 1 − − (1998) to 149 mm yr 1 − (1995) to 2.4 mm yr (1998) to 214 mm yr 1 1 erence is likely to arise because the erence in the number of check dams − − ff ff 9310 9309 ´ echal et al., 2006) as shown in Fig. 7. Groundwater ´ echal et al., 2006) in this analysis. To estimate ground- was used (Mar 1 − h for rice crops during Kharif and Rabi seasons and 7.7 mm day 3 1 , while the groundwater storage is declining at a rate of 6.1 mm yr − 1 − Finally the total storage volume of WDS was estimated from the depth-area-volume Third we analysed Watershed Development Structures (WDS) data and estimated Second, we examined the groundwater heads and draft during study period. The A detailed analysis of NSA over the last two decades indicates that the irrigated First, Fig. 6a shows the average land use variations in the catchment between 1985– their surface area (WSA) did not show any significant change during the study period and pits are unreliable. Therefore weon attempted to Google predict Earth the density data ofand and farm cultivable pits village area. based The characteristics highest includingpits correlation village and was area, observed the between irrigated total the area The village density estimated area, of total which farm number was of then farm used pits to in estimate therelationship HSC the was farm developed 1950 pits (in from number. 2004). these field structures survey. This haseach shows increased fill. that from Various the tanks 0.4 mm water existed yr in interception the by catchment at the start of the study period and ferences between these twoconstruction data cost of sets. a This farming, di pit whereas is check low and damsis it significant can can discrepancy only be between built bedata the without and farm built any the pit Government Government by data, numbers fund- Government it observed was organisations. from concluded that As Google the Earth there statistical data for farm ponds the volumes of waterfirst captured we compared by the these statistics(Village structures of level check during data) dams with the and the farm studyage, information pits Table extracted period. collected 9). from For from Results Google the this, Earth showedamong DWMA images no the (2003 significant villages im- di whereEarth the Survey). information However, is it availableother was in villages, also both found which sets thatfarm may (DWMA there pond have & had and Google constructed been pit by check numbers; other dams however, it Government in was many departments. observed For that there were significant dif- use information has increasedbased on from an inventory 140 of mm yr wells(2004). it Overall, has it increased appears from that 110 mm significant yr occurred increases in and groundwater as extraction a rate have result the groundwater levels have declined in the HSC. results indicate that the groundwater draft estimates in the catchment based on the land and vegetable crop during both seasons were assumed (Dewandel et al., 2008). The 0.30 m yr ing a specific yieldextractions of were 0.014, estimated Mar usingland two use methods: statistics. based The on13 number inventory 280 of of (1993) to groundwater bore 31 wells wells 600per in and (2004). day the Information (7 h) on HSC was the hasrate collected average of increased number 8.1 during m from of the pumping fieldwater hours draft survey from (Table irrigation 8) practice, and average15 an mm irrigation day requirements average of pumping 10 mm day Kharif season the overallfed percentage rice of crop rice arealand remained was use constant, converted change but to in 40 the irrigate. % HSC Thus, of has it been the is due rain clearaverage to groundwater irrigation that expansion heads the and from most intensification. 1998 significant to 2004 appeared to be declining at a rate of increased from 23 % to33 %. 33 % However, it and is Netor unclear Sown whether whether Area the these (NSA) changes changes will has be reflect decreased sustained. the from inter-annual 40 % variability crop to area (and thepercentage of area the sown net sown more area,(1985–1989) the than to average once) net 23 irrigated % has area (2000–2004) hasthe at and increased Kharif from least from and 7 8 doubled % % Rabi (Fig. (1985–1989) seasons to 6b). respectively 17 (Table % As 7). (2000–2004) a It in is also observed that during the be intercepted by these structures. 1989 and 2000–2004. The comparison2004 of land shows use that changes from theLands 1985–1989 Forest (RL) to (F) 2000– has area reduced has slightly not from changed 31 % and to remained 28 %, at Current 6 %, Fallow Range (CF) lands have series of hydrological structures during study period and the volume of water that could 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | . 1 1 − er- − ff , which is 1 − , respectively. 1 − respectively. Given from 1984 to 2001 1 0.29 m yr 1 − − ± (i.e., assumed that the 1 6.7 mm yr − ± yr 1 − 3.0 mm yr 2.6 mm yr ± capture increased at the rate of ± . The streamflow simulated by the 1 ff 3.5 − and 10.8 − 1 − and 1 − 9312 9311 to 32 mm yr 0.85 mm 8 fillings ected groundwater level and storage in the catch- (2004). 1 ± ff 1.6 mm yr − 1 − ± ). Overall, the rate of change of observed and model 1 3.5 mm yr − over this period, it is likely that there was both a de- ± , or 2.0 1 1 − 3.6 − − 1 yr − (Sylvain et al., 2007). 1 of decrease in groundwater storage. A study carried out in the Musi − 1 over 1998–2004 and that groundwater storages are only declining − (1995) to 28.4 mm yr 1 − 1 ) to 2004 (19 mm yr 1 − − 0.10 mm filling 5.9 mm yr ± ± Given that annual groundwater extraction rates have increase by around 40 mm yr The change in irrigated area has a Estimates of groundwater extractions based on inventory of wells and land use statis- It is also likely that irrigation practice has changed in the past two decades in the Our analysis of catchment characteristics shows changes in land use, particularly The above all changes indicate that evapotranspiration from the catchment must be 0.24 Large changes in groundwater levelswhich are may be not because observed overall recharge in mightfrom spite has irrigation increased of and due increased WDSs to increased pumping, and recharge also due to reducingto base flows 75 in mm streams. yr by an averagecline of 6 in mm yr baseriod. The flow WDS andThe information an WDS collected data increase suggest (1995–2005) in only show recharge that a the limited in runo increase the in catchment recharge. over this pe- tics show increasedThere rates is of some 7.2 evidenceperiod (Fig. 1998–2004, although 7) it of isterns, likely increasing that so rates inter-annual variability of it influences groundwaterspecific is these yield decline pat- hard values over to used the in draw this firm analysis conclusions. which needs There some is verification also in the some future. uncertainty in the favoured over dry crops in the dry season now. ment. We examined 11 observationserved wells that for the the groundwater period levels6.1 from decreased 1998 at to a 2004. ratecatchment It of during was 0.30 the ob- perioda 1998–2004 rate concluded of that 0.18 the m yr water table is declining at catchment. During field survey, itwithout is considering observed the that cropof the water free farmers demand. electricity are This to irrigating is utilisenumber groundwater. the mainly The of crops because statistical of data wells on the inchanged the availability evolution use with of also dry the total demonstrates crops this. favoured The over wet mix crops of in irrigated the crops wet has season, also and wet crops deficits from rainfall but laterits become availability the at main low water cost. resource for irrigation because of internal changes within the catchment, not due to changeswithin in cropping rainfall. areas; changes inof groundwater hydrological extraction; structures and changes in inirrigated the the area, catchment. which number The increased major in16 both change %) Kharif cropping in (from seasons. land Most 8 % use ofis to this was reflected 23 irrigation in %) demand in and the was Rabi the metGroundwater (from from groundwater irrigation 8 groundwater was % storage and originally to which practised is as supplemental decreasing irrigation at to satisfy a the rate of 6.1 mm yr decrease of 73 mm fromregression 105 mm model yr also show(80 mm that yr median streamflowssimulated reduced streamflows is by 61 mmthe lack from of 1980 trend in rainfall, the trend observed in the streamflows is likely to be due to Area Index (as indicated byother significant NDVI) which changes in is land directly use linked in to the irrigation study as area. there are6 no Discussion The trend tests results showednificant no declining trend significant was changes observed within inence the streamflows between during rainfall; 5-yr the however, average study sig- annual period. streamflows The of di 1980–1984 and 2000–2004 shows a 26.4 mm yr have increased significantly. The ET estimatesimages obtained show using AVHRR a remote sensing continuous(Teluguntla et increasing al., trend 2011) (Fig. of 8). 4.1 This increase in ET is mainly due to increase in Leaf (Table 10). The Surface water storage capacity of tanks and WDS has increased from 5 5 25 20 10 15 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | , t t E (7) (8) (9) (6) /d /d and (10) (11) E E 1 0 sub- − = t at ) from 1995 to ff 1 trends and less − 949 mm yr ff yr − 1 0 (1980–2004) and − , 1 = − , evapotranspiration, t P /d P (1998 to 2004). (1998 to 2004); and 1 1 (1984 to 2001); − − 1 63 mm yr − 0 implies the first bracket on the − 2 = t ) 3.0 mm 8 fillings t t ± d or from 41 mm to 6 mm (around 35 mm) 6.7 mm yr trends are d 0, and each of these estimates of d 1 R/ 1.57 mm yr ± 2.6 mm yr − d = ff ± ± t or 5.0 − 1 9314 9313 t /d 10.8 − 7.2 d 4.1 P = yr = = E/ t 1 t t d − 2 /d 5.9 mm yr /d t and groundwater trends over the period 1998–2004. /d ) − 3.6, d E E ± t t E ff − d d = R/ t P/ (1980–2004). We have several estimates of rates of change d d 1 − − R/ t 0.5(d d are the precipitation, evapotranspiration and runo 0.37 mm filling + 0 E/ t ± ) R d t t 0 t d R d − d R respectively, over the period 1998–2004. It should be noted that equat- t − 3.5 mm yr 1 and − R/ E/ d P/ ; where it is assumed that changes in soil moisture storage are negligible − ± 0 E d d 0 d t t R t E P/ E − , 3.6 + + , + − ff P 0 0 0 − 0 0 P E R P P = = 0.5(d ( t remote sensing estimate d changes in well inventory d changes in irrigation area d t = = = d = = d ) ) ) / – – – t t t Each of these terms is uncertain, as are the assumptions underlying Eq. (11). Our Our estimates of the rainfall and runo Using Eq. (11) with d In an attempt to reconcile the trends in water balance, we rearranged the simple ( ( S S ( , is balanced by the net input to the catchment from rainfall, 1900 mm yr R S/ the combination of rainfall, runo Another plausibility check is to estimate the total groundwater level decline since 1980. ing groundwater withdrawalsnegligible and recharge irrigation from volumesshould irrigation to be evapotranspiration applications, treated assumes thusgroundwater as storage these falls upper by two 6.1 boundover estimates estimates. 1998–2004. of The d groundwater data that suggests judgement is that weconfidence have in more the confidence evapotranspiration and intimates groundwater the of trends. rainfall The evapotranspiration and remote trends sensing runo appear es- to lead to a reasonable reconciliation of in turn implies− groundwater storage changes of of water resource developmentconditions in at the 1980, start we of assume the subsequent that development this phase. d represents equilibrium of evapotranspiration as follows: right hand side is zero and thus Eq.∆ (10) simplifies to: Given that significant water resource development began around 1980 and the low level Assuming that the catchment is in equilibrium at change in groundwater storage as: ∆ P E R Where stituting Eqs. (7), (8) and (9) into Eq. (6) and integrating results in an estimate of the and runo (Eq. 6). d Approximating the fluxes by linear trends allows them to be written as suggests that increased WDSsrecharge, despite within what the is catchment suggestedexisting tanks by may which the have capture DWMA. helped 26 Ingroundwater mm increase addition levels of to is the rainfall the likely when WDS, to theyalso there fill have have caused are reduced to some full base increase capacity. flow in Change discharge seepage in to from streams these largewater and structures. balance may Eq. (3)S into Eq. (6), where the rate of change of groundwater storage, tion was high (0.62 1998 and that there wasrandom sampling only of limited Google increases Earth images, fromthe we 1998 data observed obtained to that from check 2004. DWMA dams However,WDS appears information from situated in to the within be the incomplete catchment and developed that by there other could departments be than many DWMA. This structure fills 8 times in a year). Also the data suggest that the increase in intercep- 5 5 25 20 15 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | , ce space ffi , 2007. in the Krishna ff , 2002. doi:10.5194/hess-10-703-2006 , 2011. doi:10.1007/s00254-006-0468-x doi:10.1002/hyp.1059 9316 9315 , and eo-1 ali sensors, Remote Sens. Environ., 113, + , 2011. doi:10.1016/j.gloenvcha.2010.07.012 , 2011. This research is funded by Australian Centre for International Agricultural 10 m), also suggests that the remote sensing estimates of evapotran- ≤ cients for landsat mss, tm, etm ffi in england – anChang., 21, assessment 238–248, of draft water resources managementstreamflow, plans, Hydrol. Global Process., 16, Environ. 1235–1245, 2006. doi:10.3390/w3020618 coe 893–903, 2009. impacts from climate variabilityriver and basin increasing (India), water consumption Hydrol. on Earth runo Syst. Sci., 10, 703–713, tions of farm dams onMODSIM catchment 97 hydrology: Hobart, Methods 1997. and application to chafrey catchment, support tool with variablein agro-climatic semi-arid scenarios hard-rock for areas, sustainable Curr. groundwater Sci. management India, 92, 1093–1102, 2007. changes on streamflowdoi:10.1002/joc.2112 trends in a monsoon catchment,eastern Int. ethiopia, Environ. J. Geol., 52, Climatol., 147–154, 31, 815–831, Overall, it is clear that the trend in streamflow is due to anthropogenic changes, Charlton, M. B. and Arnell, N. W.: Adapting toChiew, climate F. H. change S. impacts and on McMahon, water T. resources A.:Chiew, F. Modelling H. S. the and impacts Siriwardena, L.: of Trend/change climate detection software, change 2005. on australian Chander, G., Markham, B. L., and Helder, D. L.: Summary of current radiometric calibration Cassardo, C. and Jones, J. A. A.: Managing water in a changing world, Water 3, 618–628, Bouwer, L. M., Aerts, J. C. J. H., Droogers, P., and Dolman, A. J.: Detecting the long-term Benoit, D., Jean-Marie, G., Faissal, K. Z., Shekeel, A., and Subrahmanyam, K.: A decision Beavis, S. G., Zhang, L., Evans, J. P.,and Jakeman, A. J., and Smith, D. I.: Impacts and implica- Adnan, N. A. and Atkinson,Alemayehu, T., P. Furi, W., and M.: Legesse, D.: Impact Exploring of water overexploitation the on highland lakes impact of of climate and land use during field work in India. Timvaluable Peterson suggestions and on Murray Peel rainfall (The and University groundwater of Melbourne) analysis provided in this paper. References International Water Management Institute (IWMI), ICRISAT, Hyderabad provided o work and Sridhar Parupalli (JNTU, Kakinada)all for the assisting Indian in Government departments the field mentioned in survey. Thanks this are paper due for to providing valuable data. The particularly increasing irrigation and groundwater extractions,in as well interception as some by increase total WDSs sustainable in resource availability, the whichincrease suggests HSC. into water the Water shortages future usage will unless continue water in to management this practicesAcknowledgements. change. catchment nowResearch exceeds (ACIAR) through aBage John Memorial Allwright Scholarship, University Fellowship of Award Melbourne to funded the the first first author to Author. conduct The the Robert field declining groundwater discharge. Irrigation waterto use be per increasing. unit By ofbalance framework, irrigated examining it area water was seems possible fluxous to fluxes and approximately with reconcile storage groundwater the storage trends changesthese declines, in although within estimates. the significant a vari- uncertainty simple exists in water 7 Conclusions This paper considers hydrologicferent trends aspects and of compares anthropogenicdemonstrated the that changes water there are in balance no dif- statisticallythere of significant are trends the clearly in trends annual Himayat over rainfall, time whereas trends Sagar in in Catchment catchment land streamflows. in These use areand India. and associated groundwater water with It levels management. are is Increases declining.tures in It such irrigated is as area likely tanks, that have increases check occurred in dams recharge and from percolation struc- tanks have occurred, together with tively. Given that depthsince to 1980 water is table isspiration trends currently are around the 10 most plausible m of (implying the the three. decline Using a specific yield of 0.02 as above, the declines would be 7, 29 and 104 m respec- 5 5 25 30 20 15 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | , , 2009. doi:10.1111/j.1752- doi:10.5194/hess-14- cient methodology for ffi , 2008. , 2006. doi:10.5194/hess-15-1979-2011 doi:10.1029/2007WR006767 , H., Rost, S., and Gerten, D.: Future water ff ects of climate and water use on base-flow trends 9318 9317 ff doi:10.1002/hyp.6738 ´ edir, M.: Impact of changing climate in the kairouan cients of irrigated crops at watershed and seasonal ffi , 2010. , 2011. ´ odar, J.: Streamflow trends in Europe: evidence from a dataset doi:10.1016/j.jhydrol.2006.02.022 ´ edric, M., Mohamed, W., Subash, C., and Benoit, D.: Percolation , 2008. ´ erome, P., C , 2010. ciency of an artificial tank in semi-arid hard rock aquifer context, South India, International ´ echal, J. C., Dewandel, B., Ahmed, S., Galeazzi, L., and Zaidi, F. K.: Combined estimation of ffi in the lower klamath1688.2008.00212.x basin, J. Am. Water Resour. As., 44,Asia 1035–1052, Environment and Social Development Department, 2005. S.: Development and applicationof of watershed a structures comprehensive and simulationof irrigation model wet water to walnut use evaluate creek on impacts watershed, streamflow kansas, USA, and J. groundwater: Hydrol., TheChanges 236, case 223–246, in 2000. land cover, rainfallbasin and – stream Ethiopia, flow Hydrol. in2011. Earth Upper Syst. Gilgel Sci., Abbay 15, catchment, 1979–1989, Blue Nile availability for global foodto production: global The change, potential Water of Resour. Res., green 45, water W00A12, for increasing resilience S., Fendekova, M., andof near-natural J catchments, Hydrol. Earth Syst. Sci., 14, 2367–2382, e Water Resources Association, 13th World Water Congress, 2008. evapotranspiration estimates from heterogeneous land surfaces, 19thon International Modelling Congress and Simulation, Perth, 2011. fed agriculture on downstreamdoi:10.1016/j.agwat.2011.08.013 flow in a semi-arid basin, Agr. Water Manage., 100, 36–45, 2367-2010 source management in1435, the 2007. musi catchment, India, MODSIM-2007, Christchurch, 1429– L., Ambili, G.,dus Qureshi, and A., Pant, thedoi:10.1080/02508060.2010.512996 D., ganges: Xenarios, River S., Singh, basins R., under and extreme Smakhtin, pressure, V.: The Water in- Int., 35, 493–521, Report No. 139, 2001. specific yield and natural recharge inJ. a Hydrol., semi-arid 329, groundwater basin 281–293, with irrigated agriculture, Detecting changes in streamflow responseFarm to dam changes development in in non-climatic the catchment murray-darling conditions: basin, australia, J. Hydrol., 262, 84–98, 2002. M.: Ecological study ofpradesh, osmansagar india, and 12th World himayatsagar Lake lakes Conference, in Taal 2007 greater Jaipur, hyderabad, India,catchment 2007. andhra management in semidrology arid and Watershed tropics Management, of Hyderabad, india, 2006. 2nd International Conference on Hy- cascades: A methodologyInstitute, based Colombo, 1997. on rapid assessment, International Water Management at a catchment scale, MODSIM-2007, Christchurch, 2007, estimating irrigation returnscale, flow Hydrol. coe Process., 22, 1700–1712, hydrological basin (central tunisia), J. Environ. Sci. Eng., 5, 682–688, 2011. World Bank: Drought in andhra pradesh: Long term impacts and adaptation strategies, South Van Kirk, R. W. and Naman, S. W.: Relative e Rientjes, T. H. M., Haile, A. T., Kebede, E., Mannaerts, C. M. M., Habib, E., and Steenhuis, T. S.: Teluguntla, P.,Ryu, D., George, B. A., and Walker, J.: Impact of spatial scale on remotely sensed Ramireddygari, S. R., Sophocleous, M. A., Koelliker, J. K., Perkins, S. P., and Govindaraju, R. Rockstrom, J., Falkenmark, M., Karlberg, L., Ho Sylvain, M., J Stahl, K., Hisdal, H., Hannaford, J., Tallaksen, L. M., van Lanen, H. A. J., Sauquet, E., Demuth, Masih, I., Maskey, S., Uhlenbrook, S., and Smakhtin, V.: Impact of upstream changes in rain- Sylvain, M., George, B., Gaur, A., and Nune, R.: Groundwater modelling for sustainable re- Sharma, B., Amarasinghe, U., Xueliang, C., de Condappa, D., Shah, T., Mukherji, A., Bharati, Kalpataru Research Foundation, K.: Watershed development, Kalpataru Research Foundation, Mar Schreider, S. Y., Jakeman, A. J., Letcher, R. A., Nathan, R. J., Neal, B. P., and Beavis, S. G.: Hanumantha Rao, T.: Innivation participation technologies for water harvesting structures & Gurunadha Rao, V. V. S., Suryanarayana, G., Prakash, B. A., Mahesh Kumar, K., and Ramesh, Sakthivadivel, R., Fernando, N., and Brewer, D. J.: Rehabilitation planning for small tanks in George, B., Malano, M. H., and Davidson, B.: Integrated water allocation-economic modelling Dewandel, B., Gandolfi, J. M., de Condappa, D., and Ahmed, S.: An e Chulli, B., Favreau, G., Jebnoun, N., and B 5 5 25 30 20 25 20 15 10 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | (mm) Average ) (m) ◦ )( ◦ Lat( Long Elevation ) period (m) rainfall ◦ 9320 9319 )( ◦ Latitude( Longitude Data Elevation annual station name Rainfall The location details of observation wells in HS catchment. Details of rainfall stations distributed in and around HS catchment. District name Mandal nameRangareddy VillageRangareddy name ChevellaRangareddy ChevellaRangareddy ShabadRangareddy Pudur AlurRangareddy Pudur ChevellaRangareddy Pudur ShabadRangareddy PargiRangareddy Shamshabad KandlapallyRangareddy Shamshabad Pudur 17.13 PalmakoleRangareddy Rajendranagar 17.33 Peddamrthial 78.07 Peddagollaapally Katedan Rajendranagar 17.33 78.07 17.04 17.24 Kuduvantapur Sivarampalli 78.14 78.02 78.39 17.22 17.19 642 17.15 77.99 78.30 631 17.22 77.90 17.33 644 17.32 643 78.99 581 78.44 78.44 636 572 666 680 530 535 Station code 14111221412120 Kondurg1413123 Farooqnagar1414121 Kothur 17.031516113 Keshampet 17.011517121 Rajendranagar 78.17 17.39 Moinabad1518117 78.04 16.981529122 Chevella 17.14 78.401530128 Pargi 78.33 1980–2004 1990–2004 17.31 78.261531119 Pudur1532116 Shabad 17.32 1980–2004 78.25 1990–2004 Shamshabad1533111 634 1990–2004 639 Maheswaram 78.12 17.12 17.21 17.23 1990–2004 535 17.19 17.18 566 700 77.94 645 78.38 598 1980–2004 77.98 78.41 78.16 775 607 590 1980-2004 1980–2004 625 627 1990–2004 1990–2004 1980–2004 707 585 720 793 677 593 646 780 911 893 744 623 Table 2. Table 1. Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Gully control ) 3 volume Average Average depth (m) ) (m 2 pits pits/ponds channels Sunken Farm Feeder Average 9322 9321 area (m erent watershed development structures collected from Mini- tanks structures ff percolation Check DamsPercolation TanksMini-Percolation TanksSunken PitsFarm Pits/PondsFeeder Channels 750Gully 1650 Control Structures 1000 2.0 3.0 30 1.2 28 16 1500 4950 3 1200 0.5 2.0 1.0 0.5 15 56 16 1.5 Structure surface dams tanks Check Percolation The watershed development structures within HS catchment extracted from collected Area-Volume particulars of di 19951997 1431998 10919992000 80 38220012002 33 82003 24 52004 40 29 55 28 – 4 1 – 105 8 11 2 – 4 355 691 – 2504 – 27 9 9 1 3 6 303 3 178 29 – 65 7 4 76 270 – 4 – – 2788 1149 2190 2553 20 12 3 – – 2 424 – – – 133 40 Year Table 4. the field survey. Table 3. data (DWMA). Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | erent time steps. ff Streamflow (mm) 2.072.07 0.03 0.03 1980–2004 1990–2004 − − 1980 1990 2000 2004 9324 9323 Z-statistic p-value Z-statistic p-value (mm) Rainfall Spearman’s rho Spearman’s rho 0.25 0.80 0.16 0.87 Test 25th50th75th 596 693 36 844 80 149 25 56 105 13 30 56 9 19 36 Percentile Change in magnitude of streamflows at di Results of trend test on rainfall and streamflows. Streamflows Mann-Kendall Rainfall Mann-Kendall 0.16 0.87 0.21 0.83 Table 6. Table 5. Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | used of Wells Number used of Wells Number erent time periods. ff 9326 9325 days hours (Kharif Season) Average Average pumping pumping number of number of (Rabi Season) per day (Rabi Season) Average Average Average (% of NSA) (% of NSA) (% of NSA) rainfed area irrigated area irrigated area (Kharif season) (Kharif season) (Rabi season) No. of samples Year 1985–19901991–19961997–20012001–2004 93 87 81 77 7 13 19 23 8 9 13 17 Groundwater extraction survey particulars during field survey. Average variations in net sown area at di Status GW SafeSemi-CriticalCriticalOver-Exploited 15 15 10 15 120 120 115 120 7 7 7 7 All All All All 50 % 40 % 70 % 50 % Table 8. Table 7. Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | S is Cul area Village Irrig. area T FP CD R Rainfall Annual Surface area FP R 9328 9327 during the rainfall of tanks month (mm) (mm) (ha) CD S FP are Google Earth survey check dams, and farm pits, SS CD & S image Date of Year 19811989 14 October2000 21 November 26 October 2012 79.20 41.10 0.00 854 774 760 1409 1486 680 FP are records available on check dams and farm pits with DWMA, Irrig. Area and Details of water surface area by tanks existed in HS catchment. Data comparison between DWMA and Google Earth for 25 villages, where GW Village Name Soils GW CD & R Cul Area are Irrigated area and Total cultivable area in the village. 12 Ammapalle3 Devarampalle4 Komerabanda5 C C Ganisimiyaguda6 C C Farooqnagar7 Cri Golkonda Cri8 Kurd Cri Gandiguda C Cri9 GC Nagaram10 Sriramnagar Cri11 Cri Chegur 0 7 GC12 Ibrahimpalle 2 413 L Cri GC Kothur 50 4314 Chevella 41 NA NA C 31 0 Cri15 3 Akhanpalle Cri NA R 116 Shubanpur NA NA 40 OE17 50 0 Yabajiguda NA Cri NA C18 NA C C Peddamunthal NA 0 1419 28 L Niz-Medipalle NA C NA20 OE 1 C 18 OE Anantharam 313 OE 381 45 4121 30 C 231 Khandlapalle OE 3 NA22 Safe 42 287 Safe Bangaliguda NA GC23 64 11 11 Kothwalguda Safe 30 GC 195 NA NA24 81 52 5 NA Safe Narkhuda NA C 105 1925 Safe 6 Nagireddyguda NA 0 75 C 5 NA 12 45 NA Sajjanpalli 15 280 6 C 51 S-Cri 16 0 82 50 NA 40 178 297 940 S-Cri C NA 11 18 577 0 5 37 NA S-Cri 142 55 384 3136 GL 11 NA 66 0 S-Cri 54 NA 12 43 3 9 165 280 NA 1962 NA S-Cri NA 103 NA 0 37 1205 NA 10 298 30 27 NA 1318 NA 556 2 24 65 69 221 871 74 645 NA NA 103 335 10 718 59 2923 52 733 NA 241 NA NA 49 67 688 NA 803 78 19 NA 43 456 33 1109 17 950 455 397 29 1063 618 267 205 22 400 167 223 245 180 288 124 234 31 375 180 169 S No. area (ha) (ha) (ha) Table 10. the Groundwater status, S R Table 9. T Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

imayat

of river Krishna basin

basin - Sunken PitSunken Check DamCheck in Musi Sub

Watershed Development Structures H in Percolation Tank HSC)

(

9330 9329 types of different

tank and

Percolation Tank ) - B water water

(

)

A of . Farm Pit (

Mini Figure: hotos Location of Himayat Sagar Catchment

: P Figure: atchment 1 c : (A)

2 Tank agar

location of Himayat Sagar Catchment (HSC) in Musi Sub-basin of Krishna river Figure Figure S districts covered by HSC, drainage network, locations of HS reservoir, rain gauge

Figure (B) Districts covered by HSC, drainage network, locationsof reservoir, HS rain gauge stations and ground observationwater wells Pictures of tank and Watershed Development Structures in HSC. (B) Fig. 2. (A) basin. stations and ground water observation wells. Fig. 1. Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

(mm) Streamflows

0 300 200 100

2007 1998 locations the Himayatin Sagar catchment Streamflows (mm)Streamflows

n survey 9332 9331 1989 to theto average rainfallannual the Himayatin Sagar catchment

roundwater extractio Rainfall (mm) Rainfall 1980 and Streamflows in HS Catchment HS in Streamflows and streamflows 0 of Time Series of Average Annual Rainfall Rainfall Annual Average Series of Time

400 800 1200

Detailed map of g

: 3 Rainfall (mm) Rainfall : Variation 4

Figure Figure Times series of average annual rainfall and streamﬂows of HS catchment. Location map of groundwater extraction survey samples. Figure Figure Fig. 4. Fig. 3. showsresiduals the against predicted Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

2004. -

at different time trends and rainfall percentiles percentiles and rainfall at different time trends

04 - 2000 04 - 2000 showsresiduals the against predicted t (FRST), Range lands (RNGB)

2000

1990 2004

NSA

99 - 980 1995 99 - 1 1995 2000-04

(mm)

Residuals IrrigatedCrops (Kharif) IrrigatedCrops

75 P (mm) CF

Model

50 P Runoff at different time trends and rainfall percentiles percentiles and rainfall at different time trends

94 - sion model of rainfall-runoff, (b) Plot rainfall-runoff, (b) Plot sion model of 1990 94 - Runoff 1990 25 P

Runoff

RNGB

1990-99 ) t Rainfall (mm) R ‐ Predicted

Observed

showsresiduals the against predicted erent time trends and rainfall per-

89 - t+b)(R 1985 2000 1990 2004 89 - A:Regression 1985 * 0.76 ﬀ 0.014 0.45 512 980 (a FRST

‐

1 = = = = = 2000-04

Predicted

2 t

areas within Net sown area sown Netwithin areas

(mm) plot shows the residuals against pre- R R b a Q

C: Trends of Streamflow TrendsC: Residuals

B: 0 400 800 1200 75 P (mm)

1980-89 0 100 200 300 (A): Land use change in HS HS Catchment in change use Land (A): Vs 0 100 200 300 0

(B) Model 50 (B): Variation in Rainfed and Irrigated Irrigated and Rainfed in Variation (B): 0 0

0 50 P Runoff , 250 200 150 100 0

45 30 15 75 50 25 Irrigated Crops (Rabi) Crops Irrigated Rainfed Crops (Kharif) Crops Rainfed .

50 50

300 200 100 ﬀ

sion model of rainfall-runoff, (b) Plot sion model of

100 ‐

100 100

Runoff 25 P

Predictied Runoff (mm) Runoff Predictied

(mm) Runoff Simulated Area Catchment Total in % ‐

(mm)

Residulas percentiles and rainfall at different time trends Runoff (%) area sown Net

1990-99 ) Figure 5: (a) Linear regres Figure 5: (a) of streamflows in magnitude Change values, (c) Page 29 of 31 Page t 2004. Rainfall (mm) : (A) Over all land use details of major classes such as Fores - R ‐ 6 9334 9333 Predicted

Observed

04 - 2000 04 - t+b)(R 2000 3 4 5 1 2 A:Regression * 0.76 Figure Current Fallow lands (CF), Net sown area (NSA), and in HS catchment for last two decades, (B) The change in rainfed and irrigated crops Netwithin sown area of catchment the from 1985 0.014 0.45 512 (a

‐

2000 1990 2004 = = = = =

Predicted

2 t

980

R R b a Q C: Trends of Streamflow TrendsC: 1 2000-04 t (FRST), Range lands (RNGB)

B: (mm) 0 400 800 1200

Residuals 1980-89

0 100 200 300

75 P

NSA

0 100 200 300 (mm)

99 - 1995 99 - 50 1995 Vs 0

250 200 150 100 Model 0

50 50 P 50 300 200 100 Runoff

‐

IrrigatedCrops (Kharif) IrrigatedCrops

100

Predictied Runoff (mm) Runoff Predictied (mm) Runoff Simulated ‐ sion model of rainfall-runoff, (b) Plot sion model of (mm) Residulas CF Runoff 25 P

Runoff

Figure 5: (a) Linear regres Figure 5: (a) of streamflows in magnitude Change values, (c) Page 29 of 31 Page 29 of

1990-99

)

Rainfall (mm)

94 - R 1990 94 - ‐ 1990 Predicted mm

Observed RNGB 3 4 5 1 2 t+b)(R A:Regression * 0.76 0.014 0.45 512 (a

‐

= = = = =

Predicted

t 2 change in magnitude of streamﬂows at di

R R b a Q

C: Trends of Streamflow TrendsC:

89 - 1985 89 - B: 1985 0 400 800 1200 1980-89 0 100 200 300 FRST (C) 0 100 200 300 0 the change in rainfed and irrigated crops within Net sown area of the catchment areas within Net sown area sown Netwithin areas 50 0 250 200 150 100 0 over all land use details of major classes such as Forest (FRST), Range lands

50 300 200 100

linear regression model of rainfall-runo

‐

100 100

Predictied Runoff (mm) Runoff Predictied HS Catchment in change use Land (A): (mm) Runoff Simulated ‐ (mm) Residulas (B) (B): Variation in Rainfed and Irrigated Irrigated and Rainfed in Variation (B): 0 0

30 15 45 75 50 25 Rainfed Crops (Kharif) Crops Rainfed (Rabi) Crops Irrigated

Figure 5: (a) Linear regres Figure 5: (a) of streamflows in magnitude Change values, (c) Page 29 of 31 Page 29

100

% in Total Catchment Area Catchment Total in % Net sown area (%) area sown Net 3 4 5 1 2 : (A) Over all land use details of major classes such as Fores 6

Fig. 6. (A) (RNGB) Current Fallow landsdecades, (CF), Net sown area (NSA), and in HS catchment for last two from 1985–2004. centiles. dicted values, Fig. 5. (A) Figure Current Fallow lands (CF), Net sown area (NSA), and in HS catchment for last two decades, (B) The change in rainfed and irrigated crops Netwithin sown area of catchment the from 1985 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

Groundwater Extractions (mm) Extractions Groundwater

1999 5 0 20 15 10 25

catchment

2004 1996

2003

1993 2002

0.30x + 2.47 + 0.30x R² = 0.58 = R² -

2001 y = = y 1990 9336 9335

y = 4.11x + 598.56 4.11x = y 2000 1987

level and extractionsin Himayat Sagar 1999

Change in Groundwater in Fluxes Change 1998 1984 Rainfall (dm) Rainfall (m) Level Groundwater (mm) perIrrigation as Extractions Groundwater (mm) Inventory Wellper GW as Extractions Groundwater of groundwater

s 500 750 700 650 600 550 0 5 Trend of Evapotranspiration Trend HSC in (mm)

rend

Evapotranspiration (mm) Evapotranspiration Groundwater Level (m) Level Groundwater The : 7 Change in Evapotranspirations in the HS catchment estimated using AVHRR data and The Trend of groundwater levels and extractions in HS catchment.

: Change evapotranspirationsin the Himayatin Sagar catchment estimated using AVHRR 8 Figure Fig. 8. remote sensing techniques. Fig. 7.

Figure Figure data and remote sensing techniques