Consumptive Water Use Analysis of Upper Rio ... - ACS Publications

Subscriber access provided by ATHABASCA UNIV

Article

Consumptive Water Use Analysis of Upper Rio Grande Basin in Southern Colorado Jonathan Dubinsky, and Arunprakash T Karunanithi Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.6b01711 • Publication Date (Web): 10 Nov 2016 Downloaded from http://pubs.acs.org on November 16, 2016

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Environmental Science & Technology is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 28

1 2 3 4 5 6 7 8 9 10 11

Environmental Science & Technology

Consumptive Water Use Analysis of Upper Rio Grande Basin in Southern Colorado Jonathan Dubinsky and Arunprakash T. Karunanithi* Center for Sustainable Infrastructure Systems, University of Colorado Denver, Denver, CO- 80217, USA *1200 Larimer Street, Denver, CO 80217. Phone: 303-556-2370 Fax: 303-556-2368 email: [email protected]

12

Abstract

13

Water resource management and governance at the river basin scale is critical for the

14

sustainable development of rural agrarian systems in the West. This research applies a

15

consumptive water use analysis, inspired by the Water Footprint methodology, to the

16

Upper Rio Grande Basin (RGB) in south central Colorado. The region is characterized by

17

water stress, extended drought, declining land health, and a depleting water table. We

18

utilize region specific data and models to analyze the consumptive water use of RGB.

19

The study reveals that, on an average, RGB experiences three months of water shortage

20

per year due to the unsustainable extraction of ground water (GW). Our results show that

21

agriculture accounts for 77% of overall water consumption and it relies heavily on an

22

aquifer (about 50% of agricultural consumption) that is being depleted over time. We find

23

that, even though potato cultivation provides the most efficient conversion of ground

24

water resources into economic value (m3 GW/$) in this region, it relies predominantly

25

(81%) on the aquifer for its water demand. However, cattle, another important

26

agricultural commodity grown in the region, provide good economic value but also relies

27

significantly less on the aquifer (30%) for water needs. The results from this paper are

28

timely to the RGB community, which is currently in the process of developing strategies 1 ACS Paragon Plus Environment


29

for sustainable water management.

30

Introduction

31

Water and energy constitutes two of the most important resource use issues of the century

32

as there are limits to the extent that humanity can continue to increase its appropriation of

33

fossil fuel resources and freshwater from the natural environment1. Further, water and

34

energy interdependencies and supply constraints have been recognized by researchers to

35

pose significant risks that can potentially and unintentionally shift overall impacts

36

geographically and temporally

37

resources needed for the environment as well as human made products (e.g. agricultural

38

produce) and processes (e.g. power plant cooling) across nations and sub-regions is the

39

necessary first step towards addressing water use issues2,3.

40

an approach that provides a useful framework to quantify fresh water usage along the

41

entire supply chain5. WF has been previously used to assess both direct consumptive

42

water use and indirect embodied water content of individual products such as milk and

43

clothes6, as well as to assess entire nations and the global system as a whole8,9. However,

44

this paper, which pulls certain concepts from WF, focusses only on consumptive water

45

use of a regional system with an aim to provide data and analysis for both the river basin

46

water users and water managers10–13. . Note that this analysis is based on water

47

consumption as opposed to the more conventional water withdrawal metric, in that a

48

consumptive water use metric recognizes the interconnectedness of the hydrologic cycle

49

and appropriately allocates evaporation, return flows, irrigation inefficiencies, and other

50

withdrawn but “unused” water3.

2,4

. In this context, proper quantification of fresh water

2 ACS Paragon Plus Environment

Water Footprint (WF) 3,6,7 is

Page 2 of 28

Page 3 of 28


51

The San Luis Valley (SLV) or Upper Rio Grande Basin (referred to in this research as

52

RGB), is a high altitude agricultural valley in South Central Colorado that covers roughly

53

21,000 km2 (8,000 square miles). It has an average elevation at the valley floor of 2,300

54

m (7,600 ft.) above sea level with an average annual precipitation of 222 mm (9 in). It is

55

a snowmelt driven system, with the majority of the water supply coming from river and

56

stream flows from the surrounding mountain ranges. Hay production and pasturelands

57

utilize some of the snowmelt while much of it flows into the massive aquifer that

58

underlies the entire valley, a portion of which is pumped back for irrigation. It is also

59

important to note that not all of the water that flows into the RGB is “owned” by the

60

region. Two major interstate compacts, the Rio Grande Compact (1938)15 and the

61

Amended Costilla Creek Compact (1963)14,, require the SLV to allocate water to

62

downstream states based on the annual snowmelt. Along with its unique climate and soil,

63

this precious water supply in this high desert region is what allows the SLV to be the

64

nation’s second largest region for potato cultivation, the producer of the country’s most

65

nutrient rich alfalfa, and the first place in North America to grow quinoa. Barley is

66

another important crop grown here and SLV is the main supplier to Coors Brewing

67

Company. Because of SLV’s limited population, isolated location, and the fact that its

68

natural watershed boundaries coincide closely with its political boundaries resulted in

69

EPA considering this region as an ideal study area for regional sustainability analysis16–18

70

The impacts of ground water pumping on surface water flows in the region have been

71

recognized and the extreme drought of 2002 brought the situation to a head. A robust

72

ground water11 model, developed by CDWR, shows that continuous and increasing

73

depletion of the aquifer (as monitored since the late 1970s by Davis Engineering (see 3 ACS Paragon Plus Environment


74

Figure 1)) has affected surface water flows over the last ten years and impacted

75

agriculture which relies on those flows. This region specific model provides a complete

76

water balance and paints a picture of consumptive water use in the region that includes

77

return flows, crop shortages, and native vegetation22. As agriculture is the major

78

economic activity in the region, the community has recognized the importance of

79

working towards sustainable management of the region’s water resources on which its

80

economy relies heavily19. Due to it’s farsighted and proactive nature, the local

81

community demanded legislation from the state that requires sustainable water

82

management, namely Senate Bill 04-22220 signed in 2004, which is currently being

83

implemented. As part of this bill, the Colorado Division of Water Resources (CDWR)

84

has promulgated well rules and regulations and submitted them to the Colorado Water

85

Court in the Fall of 201521. The purpose of this legislation is to ensure that the Colorado

86

water law priority system is upheld, given the now apparent impacts of ground water

87

pumping on surface water flows. Colorado uses the “first in time first in right” prior

88

appropriation system of water law, which appropriates surface water rights to the first

89

person to divert the water for beneficial use. The RGB’s surface water was fully

90

appropriated by 1900, but as ground water at that time was thought to be delinked from

91

the surface water system, the state continued to issue well permits for ground water

92

pumping until the 1970s. The new legislation requires repayment of injurious depletions

93

of senior surface water rights from ground water pumping.

94

Another major component of the well rules and regulations, and in some regard the most

95

interesting due to the major drop in the aquifer levels that took place during the 2002

96

drought, is the requirement that the confined aquifer be maintained at the average historic 4 ACS Paragon Plus Environment

Page 4 of 28

Page 5 of 28


97

levels similar to the time period of 1978 to 2000. This is the first legislation of its kind in

98

the country and may set a precedent for future sustainable aquifer management

99

legislations. The State Engineer’s Office and the CDWR’s Division 3 Engineer, who

100

administers the Rio Grande Basin, is responsible for managing and enforcing the ground

101

water rules. Also allowed under the legislation is the formation of ground water

102

management sub-districts of the Rio Grande Water Conservation District (RGWCD).

103

These entities are tasked with managing their water use, replacing injurious depletions to

104

the senior surface water rights holders through replacement water, financial water saving

105

incentive programs, and restoring and maintaining a sustainable aquifer within the

106

parameters of the legislation21.

107



108 109

Figure 1 Unconfined aquifer level in the RGB over time.

110 111

Simultaneously, Governor John Hickenlooper issued an Executive Order in 2013

112

requiring the Colorado Water Conservation Board (CWCB) to develop a statewide water

113

plan. Each of the state’s nine river basins, including RGB, was to develop their own

114

Basin Implementation Plans (BIP). The Rio Grande Basin Roundtable (RGBRT), by

115

involving all major stakeholders and water users, developed a comprehensive BIP (Rio

116

Grande Basin Implementation Plan-RGBIP23) that lays out projects, goals, and priorities

117

for the basins future. The RGBIP, which was completed and published in the summer of

118

2015, is focused on achieving a balance of competing water needs through cooperative

119

management of water resources23. The RGBIP outlines detailed plans and allocated funds

120

for improving soil health to increase water holding capacity, improving stream flow 6 ACS Paragon Plus Environment

Page 6 of 28

Page 7 of 28


121

forecasting, irrigation improvements, head gate and ditch restoration projects, and the Rio

122

Grande headwaters restoration project. It also emphasizes the importance of maintaining

123

a healthy stream corridor to achieve efficient compact deliveries at the state line. The

124

BIPs from across the state, which each focused on their individual basins, informed the

125

Colorado Water Plan, which was delivered to the Governor in November of 2015 and

126

will highly influence water use in the state (www.Coloradowaterplan.org). This unique

127

regional context of freshwater scarcity necessitates development of SLV specific

128

methods, models and data to understand and address the problem. In an attempt to fill

129

information and data gaps, we present a robust and descriptive, region-specific baseline

130

consumptive water use analysis (CWU) that will be available as a resource to assist local

131

decision makers who are continuing to develop plans and implement actions towards

132

sustainable water use in the RGB.

133

Methods

134

Our analysis utilizes the concept of tracking the origin (source) of water be it effective

135

rain (green) or rivers and streams (blue)

136

blue water into surface and ground water components due to the unique hydrologic

137

features of the SLV region. We characterize the water consumption in SLV into the

138

following three categories: Crops, Livestock, and Municipal / Industrial use; and we

139

consider the following three water sources: effective precipitation (green), blue surface

140

water runoff (surface/snowmelt), and blue ground water from the aquifer (ground) (see

141

Supplemental Information Table S1). The grey water component, which represents water

142

needs for pollutant discharge and dilution, was not considered in this study due to lack of

143

region specific data and interest. Since this research focuses on the water consumption

24,25

. In the present study, we also divided the



144

patterns of the region itself, we only considered water originating within the basin and

145

did not account for any upstream-embodied water of imported goods and services. In this

146

way, the analysis is different from the traditional Water Footprint methodology.

147 148 149

The consumptive water use (CWU) calculations adapted for the RGB are shown below:

=

+

150

=

_ +

_ 151 = + 152 = _ + _ + _& 153 = _ + _ + _& 154 155 156

A unique aspect of the presented regional consumptive water use assessment is that we

157

first estimate the total consumptive water use in the basin using a local ground water

158

model, and then we derive the Consumptive Water Content (CWC) of each crop from

159

this overall CWU making the results highly specific to the region. The CWC represents

160

the quantity of water needed to produce an unit of a good or service3,26. This level of

161

regional specificity was possible due to the close collaboration of our research team with

162

the Colorado Division of Water Resources (CDWR), and the use of regional data from

163

CDWR’s central database (HydroBase) that houses real-time, historic, and geographic

164

data related to water resources in Colorado. By using Rio Grande Decision Support

165

System (RGDSS) ground water model22,27, which is specifically calibrated for this region,

166

we were able to develop a robust, region-specific accounting that does not rely on global

167

averages (which is typical of consumptive water use studies). 8 ACS Paragon Plus Environment

Page 8 of 28

Page 9 of 28


168

Crop Water Use of RGB

169

The crop water consumption calculations were performed within the Colorado crop

170

consumptive water use model (StateCU) component of the RGDSS and considered the

171

entire Water Division 328. StateCU, as applied in the RGDSS, models the water budget

172

of a ditch service area by calculating the quantity of water consumed by different crops

173

using a modified Blaney-Criddle method with locally calibrated crop coefficients. In

174

addition, local data related to temperature, precipitation, rooting depths, growing season

175

starting and end dates, available water content of soils, irrigated acres, cropping patterns,

176

surface and ground water diversions, ditch conveyance and irrigation application

177

efficiencies were supplied as inputs into the StateCU model. The data was developed and

178

maintained within HydroBase22 as part of the RGDSS efforts.

179

We assessed the four major crops cultivated in the region: alfalfa, potatoes, small grains

180

(mainly barley) and meadows/pasture grass on a monthly time step from years 2000 to

181

2010. They were assessed for potential evapotranspiration, effective precipitation (EF),

182

and the remaining irrigation water requirement (IWR). Figure 2 shows a map of the

183

irrigated land acreage of various crops.



184 185

Figure 2 - The total acreage and production in the SLV averaged from 2000-2010.

186 187 188

Much like the global CROPWAT model, which many studies use to estimate crop water

189

consumption, the StateCU model is used to estimate the effective precipitation and the

190

amount of irrigation water consumed by the crops 6,10,11. Using a local consumptive water

191

use model (StateCU) coupled with a local ground water model (RGDSS) is unique and

192

critical in that there may be times when precipitation and irrigation water supplies are

193

insufficient to meet the entire crop demands, and for these instances there is a shortage

194

that may be met if the groundwater table is within the crop’s root zone. The RGDSS

195

groundwater model simulates the groundwater table and the associated crop demand

196

shortage, and if the groundwater table is within the crop-rooting zone, the groundwater

197

model can meet a portion up to the full crop demand shortage through sub irrigation.

198

Further, there may be times when all water supplies fall short of meeting the full crop

199

demands, which may affect the crop yields. Crop yield data was obtained at the county

200

level through the National Agricultural Statistics Service (NASS)29 and are presented in 10 ACS Paragon Plus Environment

Page 10 of 28

Page 11 of 28


201

table S2 (see supplementary information).

202

Due to the difference in the evaluation methods of this research and StateCU, i.e. this

203

research by crop and StateCU by ditch service area, we post processed the StateCU

204

results to quantify the individual crop consumptive water use amounts. The analysis

205

utilizes information from the Alamosa climate station as an approximation for the

206

remainder of Water Division 3 to evaluate crop demands, and then normalizes the crop

207

demands back to the Water Division 3 StateCU model results. By combining the post

208

processing results from the StateCU model and crop yield data29 we were able to

209

determine the CWCgreen, CWCsurface, and in combination with the RGDSS groundwater

210

model, the CWCground, for each of the major crops .

211

Livestock Water Use of RGB

212

We calculated the consumptive water use of livestock (CWUlivetock) in the SLV by

213

multiplying the consumptive water content (m3/ton live weight) of a livestock

214

(CWClivestock) type by the production quantity in the RGB (See supplementary

215

information S3). The three major water uses needed for calculating the CWClivestock are

216

drinking water requirement (DWR), service water requirement (SWR), and feed water

217

requirement (FWR)10. SWR is a measure of the small amount of water used for keeping

218

and maintaining the animals. The DWR and SWR were estimated using global annual

219

averages from Mekonnen and Hoekstra’s30 analysis of livestock water footprints for

220

grazing animals. In addition, under consumptive water use of livestock we also include

221

the water embodied in the feed that the livestock eat (FWR), as this water also originates

222

in the basin. The FWR, which accounts for 99% of the grazing livestock CWU, was

223

calculated based on local consumptive water content of the feed crops grown in the 11 ACS Paragon Plus Environment


224

region (see Supplementary Information table S4) coupled with the amount and feed

225

conversion efficiency (FCE) of each type of feed consumed by the livestock. FCE is a

226

measure of the quantity of feed needed to produce a certain quantity of output. ! = Σ # ∗ %

227 & = &''( )*+' 228 # =

,-. /01' 23042/ 5'06ℎ)

229 ,-. = (8* 42))'8 03)29' 230 231

A daily dry matter intake (DMI) of 3% of the body weight for adult cattle and 1.5% for

232

calves and grazing sheep in accordance with Mekonnen and Hoekstra30 and confirmed by

233

the local extension office and a local rancher was used31,32. The total forage consumption

234

values were based on the assumption that all feed requirements needed by the livestock

235

were satisfied through local resources, as is the practice in the region. The public grazing

236

lands in the region has the capacity to support the herd of cattle and sheep spending 3

237

months of the year on dry land pasture33–35, 5 months grazing on private irrigated pasture

238

and meadows, and 4 months eating baled hay grass and/or hay alfalfa31,32. The total

239

livestock headcount was obtained from NASS and since the FWR of hogs originate from

240

outside the region, and their population is insignificant (see supplementary information

241

table S3), they were not included in this study. Typically, ranchers in the SLV do not

242

finish cattle or sheep locally but tend to export live animals; therefore, we used ton live

243

animal as the unit for livestock production instead of the more conventional unit of kg

244

meat.


Page 12 of 28

Page 13 of 28


245

Municipal and Industrial Water Use of RGB

246

We calculated the consumptive water use of the municipal and industrial sector

247

(CWUM&I) based on input data used in the RGDSS groundwater model on a monthly time

248

step for the period of 2000 through 2010. The value for M&I water consumption was

249

based on the total pumping and return flows for all non-irrigation high capacity wells

250

within the RGDSS model domain, which covers the entire region. In addition to ground

251

water pumping, this sector also includes consumptive water use from reservoir

252

evaporation of surface water. It is important to note that the manufacturing and industrial

253

sector in the SLV represents only ~1% of the overall economy 19.

254

Results and Discussion

255

Total Consumptive Water Use of RGB

256

An examination of the results shows that RGB’s consumptive water use is entirely

257

dominated by agricultural activities. Crops account for 63% of the CWU of the valley,

258

followed by livestock at 13% and municipal and industrial use accounting for only 3%. In

259

addition, native vegetation accounts for about 21% of the overall consumptive water use

260

in the valley (Figure 3). The total consumptive water use (in million m3) was divided into

261

green water, surface water, and ground water (See Figure 3). By breaking up the blue

262

water CWU (CWUblue) into two components: CWUground and CWUsurface, we were able to

263

analyze, in fine detail, how the various water users draw upon specific water sources

264

(ground vs surface water).



265 266 267 268

Figure 3 - Average annual water allocation in the SLV from 2000-2010. (1 Ac-ft. = 1233.5 m3)

269

Figure 3 shows that alfalfa is the largest overall user of water followed by meadows and

270

pasture and then cattle. It is important to note that meadows and pasture are useful for

271

much more than just grazing cattle, as proven by the fact that even after allocating the

272

water needed for raising forage for cattle and sheep, the remaining meadows are still one

273

of the largest overall contributor to the CWU in the RGB. This apparent over allocation

274

of water is due in part to the fact that the majority of irrigation water used for meadows

275

and pasture is surface water that is diverted for agricultural uses during early spring and

276

summer, in accordance with prior appropriation system. In many locations, the surface

277

water is diverted from the rivers or streams across the fields to grow grass where ranchers

278

graze their cattle, put up hay for the winter, and export haylage. In addition to providing


Page 14 of 28

Page 15 of 28


279

grazing land, meadows also sustain a vast and complex network of wetlands, native

280

habitat and species.

281

Crop Consumptive Water Use of RGB

282

Figure 4 shows the breakdown of the total consumptive water use of crops (CWUcrops) in

283

the RGB as well as the CWC for each major crop. This figure should be read inside-out

284

with water demand by source type shown in the inner ring and the different crops

285

demanding that type of water represented in the outer ring. Overall, 57% of the crop

286

water requirement is met by ground water, 27% is met by surface water, and 16% is from

287

effective precipitation during the growing season. These results indicate that alfalfa is the

288

largest consumer of ground water in the valley while meadows/pasture is the largest

289

consumer of surface and green water. The Blue Water Portion (BWP), which combines

290

surface water and groundwater needed for all crops in the valley accounts for about 85%

291

of the CWUcrops. This BWP for crops in the valley is much higher than the global

292

average of 19%26, indicating that the region is much more reliant on irrigation in

293

comparison to other regions. In addition, our finding that 57% of the CWUcrops comes

294

from ground water resources has a profound and direct bearing on the long term

295

sustainability of the aquifer (a key requirement of the new Well Rules and Regulations).



296 297 298 299

Figure 4 - The crop water use allocated between CWUgreen-crops, CWUsurface-crops, and CWUground-crops as well as the virtual water content of each crop.

300 301

Livestock Consumptive Water Use of RGB

302

The livestock consumptive water use considers water needed for feed crops, drinking

303

water, and service water. In the RGB, 98% of the water needs for livestock can be

304

attributed to the feed water requirements (FWR). Figure 5 presents a breakdown of the 16 ACS Paragon Plus Environment

Page 16 of 28

Page 17 of 28


305

CWUgreen-livestock, CWUground-livestock and CWUsurface-livestock in the Valley. Overall, 40% of

306

the livestock water needs are met by green water, 30% by ground and surface water.

307

Livestock are able to utilize the sparse green water that falls in the region through dry

308

land pasture grazing in the summer months. This, along with meadows and pasture

309

grazing, is why we see such a large green water percentage for the livestock CWU. The

310

majority of the surface and ground water portion of the CWUlivestock goes to raising

311

irrigated pasture for grazing and winter hay feed.

312 17 ACS Paragon Plus Environment


313 314 315 316

Figure 5 - Livestock consumptive water use (CWUlivestock) for SLV allocated between CWUgreen-crops, CWUsurface-crops, and CWUground-crops as well as the consumptive water use content of each crop. The smaller pie graph shows that cattle in dominate livestock in the region.

317

Agricultural Products

318

Table 1 compares the CWC, Total CWU, and water source percentages for each of the

319

major agricultural products in the region. Further, we define the ground water intensity as

320

a measure of the quantity of ground water needed per ton or per dollar revenue of

321

agricultural products. The dollar value for agricultural products sold in Colorado was

322

obtained from the USDA29 using the previous 5-year average and was used to calculate

323

the ground water intensity measured in $/m3 (see supplementary information table S3 and

324

S4)

325

The results indicate that, when we use revenue as the index, potatoes have the highest

326

efficiency in converting ground water into dollars followed by sheep and cattle. Efficient

327

conversion of ground water resources to dollars is not the only measure to determine

328

what is best for the region, but it does capture two major issues related to the valley,

329

economy and a depleting aquifer. Potatoes are efficient at producing high yields (17 tons

330

/ acres) and hence have a low ground water use per dollar revenue. However, this is offset

331

significantly by the fact that they require the highest ground water portion (81%) per ton

332

of crop (see Table 1). This is in contrast to sheep and cattle, which are second in efficient

333

conversion of ground water resources into dollars but also have the lowest ground water

334

portion (~30%) per ton of any of the agricultural products in the region. Further, the

335

current consumption of blue water for crops and livestock (almost all of which is

336

exported) results in a net displacement of 1,120 million m3/year (908 thousand ac-ft.) in


Page 18 of 28

Page 19 of 28


337

the form of virtual water flows (calculated as area under the ‘blue water CWU crops and

338

feed’ curve of Figure 6) of surface and ground water.

339 340 341

Table 1 - Comparison of major agricultural products in the region from multiple perspectives. (1 Ac-ft. = 1233.5 m3)

Alfalfa Potatoes Small Grains Live Cattle Live Sheep

CWU Content - SLV (m3 t-1) 871.2 100.4 758.5 9529.9 6535.4

CWU Valley Wide (Million m3) 417.5 124.3 200.8 237.6 5.9

Surface Water Portion (SWP) % 23.1 4.5 13.7 30.6 30.1

Ground Water Portion (GRD-WP) % 61.3 81.7 74.1 29.8 30.4

Green Water Portion (GRD-WP) % 15.5 13.9 12.2 39.7 39.5

Ground Water Use / $ Revenue (m3 GW $-1) 2.61 0.41 2.26 1.69 1.54

342 343 344

Blue Water Scarcity

345

We use Blue Water Scarcity (BWS)

346

the region.

347

(WAblue) (See Figure 6).

3,10

as a metric to understand water sustainability of

BWS occurs anytime the WFblue exceeds the Blue Water Availability

: = !;3

Consumptive Water Use Analysis of Upper Rio ... - ACS Publications

Recommend Documents