Estimating Potential Climate Change Effects on the Upper Neuse Watershed Water Balance Using the SWAT Model

Climate change poses water resource challenges for many already water stressed watersheds throughout the world. One such watershed is the Upper Neuse Watershed in North Carolina, which serves as a water source for the large and growing Research Triangle Park region. The aim of this study was to quantify possible changes in the watershed’s water balance due to climate change. To do this, we used the Soil and Water Assessment Tool (SWAT) model forced with different climate scenarios for baseline, mid‐century, and end‐century time periods using five different downscaled General Circulation Models. Before running these scenarios, the SWAT model was calibrated and validated using daily streamflow records within the watershed. The study results suggest that, even under a mitigation scenario, precipitation will increase by 7.7% from the baseline to mid‐century time period and by 9.8% between the baseline and end‐century time period. Over the same periods, evapotranspiration (ET) would decrease by 5.5 and 7.6%, water yield would increase by 25.1% and 33.2%, and soil water would increase by 1.4% and 1.9%. Perhaps most importantly, the model results show, under a high emission scenario, large seasonal differences with ET estimated to decrease by up to 42% and water yield to increase by up to 157% in late summer and fall. Planning for the wetter predicted future and corresponding seasonal changes will be critical for mitigating the impacts of climate change on water resources.     

Nitrate Concentrations in Springs Flowing into the Lower Flint River Basin,Georgia U.S.A.1

Allums, Stephanie E., Stephen P. Opsahl, Stephen W. Golladay, David W. Hicks, and L. Mike Conner, 2012. Nitrate Concentrations in Springs Flowing Into the Lower Flint River Basin, Georgia U.S.A. Journal of the American Water Resources Association (JAWRA) 48(3): 423-438. DOI: 10.1111/j.1752-1688.2011.00624.x Abstract: Analysis of long-term data from (2001-2009) in four springs that discharge from the Upper Floridan aquifer into the Flint River (southwestern Georgia, United States) indicate aquifer and surface-water susceptibility to nutrient loading. Nitrate-N concentrations ranged from 1.74 to 3.30 mg/l, and exceeded historical levels reported for the Upper Floridan aquifer (0.26-1.52 mg/l). Statistical analyses suggest increasing nitrate-N concentration in groundwater discharging at the springs (n = 146 over eight years) and that nitrate-N concentration is influenced by a dynamic interaction between depth to groundwater (an indicator of regional hydrologic conditions) and land use. A one-time synoptic survey of 10 springs (6 springs in addition to the 4 previously mentioned) using stable isotopes generated δ¹⁵N-NO₃⁻ values (4.8-8.4‰ for rural springs and 7.7-13.4‰ for developed/urban springs) suggesting mixed sources (i.e., fertilizer, animal waste, and soil organic nitrogen) of nitrate-N to rural springs and predominantly animal/human waste to urban springs. These analyses indicate a direct relation between nitrate-N loading since the 1940s and intensification of agricultural and urban land use. This study demonstrates the importance of evaluating long-term impacts of land use on water quality in groundwater springs and in determining how rapidly these changes occur.     

Stable sulfur isotope ratio indicates long-term changes in sulfur deposition in the Broadbalk experiment since 1845

Archived wheat (Triticum aestivum L.) grain and straw, and soil samples from the control plot of the Rothamsted Broadbalk Experiment, located in southeastern England and established in 1843, were used to investigate the effects of dramatically changing SO2 pollution inputs on the concentrations and stable isotope ratios (delta34S) of S in the samples. Representative coal samples from UK major coal fields were also determined for delta34S. Concentrations of S showed no clear trends in either grain or straw over the 155 years from 1845 to 1999. However, grain and straw delta34S decreased rapidly from 6 to 7/1000 in 1845 to -2 to -5/1000 in the early 1970s, and since then have increased to 0.5 to 2/1000 in the late 1990s. This pattern mirrored the trend of UK SO2 emissions over the 155 years. Both grain and straw delta34S correlated strongly and negatively with UK SO2 emissions (R2 > 0.89), but the relationships were different for the pre- and post-1970 data sets. Soil delta34S also decreased considerably, from 8.2/1000 in 1865 to 3.7 to 4.5/1000 during 1965-1999. A negative delta34S value was inferred for the anthropogenic S deposited at the experimental site before 1970, and further confirmed by negative delta34S values (-6 to -10/1000) found in the coal samples from southeastern England and southern Wales. Based on the S isotope ratios, we estimated that anthropogenic S contributed 62 to 78% of the S uptake by wheat at the peak of SO2 emissions, and accounted for 28 to 37% of the topsoil S in 1965.     

The Influence of Forest Regrowth on the Stream Discharge in the North Carolina Piedmont Watersheds

This study focuses on the relationships of watershed runoff with historical land use/land cover (LULC) and climate trends. Over the 20th Century, LULC in the Southeast United States, particularly the North Carolina Piedmont, has evolved from an agriculture dominated to an extensively forested landscape with more recent localized urbanization. The regrowth of forest has an important influence on the hydrology of the region as it enhances ecosystem interaction with recent climate change. During 1920‐2009, the amount of precipitation in some parts of the North Carolina Piedmont forest regrowth area showed increasing trends without corresponding increments in runoff. We employed the Soil and Water Assessment Tool (SWAT) to backcast long‐term hydrologic behavior of watersheds in North Carolina with different LULC conditions: (1) LULC conversion from agricultural to forested area and (2) long‐term stable forested area. Comparing U.S. Geological Survey‐measured stream discharge with SWAT‐simulated stream discharge under the assumption of constant 2006 LULC, we found significant stream discharge underprediction by SWAT in two LULC conversion watersheds during the early simulation period (1920s) with differences gradually decreasing by the mid‐1970s. This model bias suggests that forest regrowth on abandoned agricultural land was a key factor contributing to mitigate the impact of increased precipitation on runoff due to increasing water consumption driven by changes in vegetation.     

Water Stress Projections for the Northeastern and Midwestern United States in 2060: Anthropogenic and Ecological Consequences

Future climate and land‐use changes and growing human populations may reduce the abundance of water resources relative to anthropogenic and ecological needs in the Northeast and Midwest (U.S.). We used output from WaSSI, a water accounting model, to assess potential changes between 2010 and 2060 in (1) anthropogenic water stress for watersheds throughout the Northeast and Midwest and (2) native fish species richness (i.e., number of species) for the Upper Mississippi water resource region (UMWRR). Six alternative scenarios of climate change, land‐use change, and human population growth indicated future water supplies will, on average across the region, be adequate to meet anthropogenic demands. Nevertheless, the number of individual watersheds experiencing severe stress (demand > supplies) was projected to increase for most scenarios, and some watersheds were projected to experience severe stress under multiple scenarios. Similarly, we projected declines in fish species richness for UMWRR watersheds and found the number of watersheds with projected declines and the average magnitude of declines varied across scenarios. All watersheds in the UMWRR were projected to experience declines in richness for at least two future scenarios. Many watersheds projected to experience declines in fish species richness were not projected to experience severe anthropogenic water stress, emphasizing the need for multidimensional impact assessments of changing water resources.     

Integrated BIosphere Simulator (IBIS) yield and nitrate loss predictions for Wisconsin maize receiving varied amounts of nitrogen fertilizer

Agriculture in the U.S. Midwest faces the formidable challenge of improving crop productivity while simultaneously mitigating the environmental consequences of intense management. This study examined the simultaneous response of nitrate nitrogen (NO3-N) leaching losses and maize (Zea mays L.) yield to varied fertilizer N management using field observations and the Integrated BIosphere Simulator (IBIS) model. The model was validated against six years of field observations in chisel-plowed maize plots receiving an optimal (180 kg N ha(-1)) fertilizer N application and in N-unfertilized plots on a silt loam soil near Arlington, Wisconsin. Predicted values of grain yield, harvest index, plant N uptake, residue C to N ratio, leaf area index (LAI), grain N, and drainage were within 20% of observations. However, simulated NO3-N leaching losses, NO3-N concentrations, and net N mineralization exhibited less interannual variability than observations, and had higher levels of error (20-65%). Potential effects of 30% higher (234 kg N ha(-1)) and 30% lower (126 kg N ha(-1)) fertilizer N use (from optimal) on NO3-N leaching loss and maize yield were simulated. A 30% increase in fertilizer N use increased annual NO3-N leaching by 56%, while yield increased by only 1%. The NO3-N concentration in the leachate solution at 1.4 m below the soil surface was 30.7 mg L(-1). When fertilizer N use was reduced by 30% (from optimal), annual NO3-N leaching losses declined by 42% after seven years, and annual average yield only decreased by 8%. However, NO3-N concentration in the leachate solution remained above 10 mg L(-1) (11.3 mg L(-1)). Clearly, nonlinear relationships existed between changes in fertilizer use and NO3-N leaching losses over time. Simulated changes in NO3-N leaching were greater in magnitude than fertilizer N use changes.     

Influence of manure application on surface energy and snow cover: model development and sensitivities

Winter landspreading is an important part of manure management in the U.S. Upper Midwest. Although the practice is thought to lead to excessive P runoff losses, surprisingly little has been learned from field experiments or current water quality models. We captured knowledge gained from winter manure landspreading experiments by modifying a mechanistic snow ablation model to include manure. The physically based, modified model simulated the observed delay in snow cover disappearance and surface energy balance changes caused by application of the manure. Additional model simulations of surface energy balance estimates of radiation and turbulent fluxes showed that during intense melting events the manure on top of snow significantly reduced the energy available for melt of the snow underneath, slowing melt. The effect was most pronounced when snowmelt was driven by both relatively high solar radiation and turbulent heat fluxes. High absorbed shortwave radiation caused significant warming of the manure, which led to substantial losses in turbulent fluxes and longwave radiation. Simulations of snowmelt also showed that manure applications between 45 and 100 Mg ha(-1) significantly reduced peak snowmelt rates, in proportion to the manure applied. Lower snowmelt rates beneath manure may allow more infiltration of meltwater compared with bare snow. This infiltration and attenuated snowmelt runoff may partially mitigate the enhanced likelihood of P runoff from unincorporated winter-spread manure.     

Projected Changes in Discharge in an Agricultural Watershed in Iowa

Our improved capability to adapt to the future changes in discharge is linked to our capability to predict the magnitude or at least the direction of these changes. For the agricultural United States Midwest, too much or too little water has severe socioeconomic impacts. Here, we focus on the Raccoon River at Van Meter, Iowa, and use a statistical approach to examine projected changes in discharge. We build on statistical models using rainfall and harvested corn and soybean acreage to explain the observed discharge variability. We then use projections of these two predictors to examine the projected discharge response. Results are based on seven global climate models part of the Coupled Model Intercomparison Project Phase 5 and two representative concentration pathways (RCPs 4.5 and 8.5). There is not a strong signal of change in the discharge projections under the RCP 4.5. However, the results for the RCP 8.5 point to a stronger changing signal related to larger projected increases in rainfall, resulting in increased trends, in particular, in the upper part of the discharge distribution (i.e., 60th percentile and above). Examination of two hypothetical agricultural scenarios indicates that these increasing trends could be alleviated by decreasing the extent of the agricultural production. We also discuss how the methodology presented in this study represents a viable approach to move forward with the concept of return period for engineering design and management in a nonstationary world.     

Culture and the environment in France

Although the French concern for environmental protection dates back several centuries, a committed movement toward environmental protection did not begin until the second half of the 19th century. The Romantic influence of Rousseau and others led to the formation of various societies aimed at protecting the French landscape.Until the most recent environmental crusades of the 1960s and 1970s, the cause of protecting the natural environment seemed to fall largely on the shoulders of scientists and anglers, who voiced their concern over increasing environmental degradation in pamphlets and recreational journals. Their pressure aided in the passage of legislation on water quality.During the 1960s, environmental organizations proliferated and, in league with student activists, played an important role in raising the environmental consciousness of the French. During the 1970s, these activists began to turn to traditional political mobilization as a way of drawing attention to their platform. Environmental activism reached its peak with the antinuclear rallies of the late 1970s. By the end of the 1970s, many environmental associations had grown up in the French culture, but the future of environmentalism remains questionable owing to a number of economic realities, including the oil crisis, which made nuclear power much more acceptable to the public.     

Hydrological Variability and Uncertainty of Lower Missouri River Basin Under Changing Climate

The lower Missouri River Basin has experienced increasing streamflow and flooding events, with higher risk of extreme hydrologic impacts under changing climate. The newly available North American Regional Climate Change Assessment Program (NARCCAP) climate projections were used as atmospheric forcing for Soil and Water Assessment Tool (SWAT) model which runs with varying potential evapotranspiration (PET) methods to assess the hydrological change and uncertainty of 2040‐2069 over 1968‐1997. The NARCCAP temperature and precipitation predictions were refined using a bias correction method. The results show that, following the seasonal variability of precipitation, various water fluxes would increase in most seasons except the summer. Expected precipitation tends to increase in intensity with little change in frequency, triggering faster surface water concentration to form floods. The greatest streamflow increase would occur from November to February, increasing by around 10% on average. An increase of 3% occurs in the other months except for July and August in which river discharge decreases by around 2%. The climate predictions contribute more uncertainty annually, but PET algorithms gain more influence in winter or when other weather factors such as wind play a relatively more important role on evapotranspiration flux. This study predicts an even wetter environment compared to the historically very wet period, with the possibility of more flooding.     

Pricing behaviour and market power in North American non-ferrous metal industries

The paper considers the degree to which declining market power explains modifications in pricing behaviour observed since the late 1970s in the North American aluminium, copper, lead and zinc industries. More precisely, it relates those changes in pricing policies to the price elasticity of demand facing the dominant strategic group in each industry, the cost elasticity of supply and to the management's ability to coordinate or internalize conduct decisions. The results suggest that the firms in the copper and lead industries do not hold as a group any form of market power. In the case of the aluminum industry, a notable increase in the price elasticity of demand since the end of the 1970s, a sustained decrease in the concentration ratio and a rigid production process are weakening the presence of market power in that industry. The results are inconclusive in the case of the zinc industry since the determinants of market power move in opposite directions.     

Potential Impacts and Management Implications of Climate Change on Tampa Bay Estuary Critical Coastal Habitats

The Tampa Bay estuary is a unique and valued ecosystem that currently thrives between subtropical and temperate climates along Florida’s west-central coast. The watershed is considered urbanized (42 % lands developed); however, a suite of critical coastal habitats still persists. Current management efforts are focused toward restoring the historic balance of these habitat types to a benchmark 1950s period. We have modeled the anticipated changes to a suite of habitats within the Tampa Bay estuary using the sea level affecting marshes model under various sea level rise (SLR) scenarios. Modeled changes to the distribution and coverage of mangrove habitats within the estuary are expected to dominate the overall proportions of future critical coastal habitats. Modeled losses in salt marsh, salt barren, and coastal freshwater wetlands by 2100 will significantly affect the progress achieved in “Restoring the Balance” of these habitat types over recent periods. Future land management and acquisition priorities within the Tampa Bay estuary should consider the impending effects of both continued urbanization within the watershed and climate change. This requires the recognition that: (1) the Tampa Bay estuary is trending towards a mangrove-dominated system; (2) the current management paradigm of “Restoring the Balance” may no longer provide realistic, attainable goals; (3) restoration that creates habitat mosaics will prove more resilient in the future; and (4) establishing subtidal and upslope “refugia” may be a future strategy in this urbanized estuary to allow sensitive habitat types (e.g., seagrass and salt barren) to persist under anticipated climate change and SLR impacts.     

HISTORICAL AND ESTIMATED GROUND WATER LEVELS NEAR WINNIPEG,CANADA, AND THEIR SENSITIVITY TO CLIMATIC VARIABILITY1

ABSTRACT: Long term well hydrographs and estimated ground water levels derived from hydroclimatic and biological data were used to evaluate trends within the Upper Carbonate Aquifer (UCA) near Winnipeg, Canada, during the 20th Century. Ground water records from instruments have been kept since the early 1960s and are derived from piezometers in the overlying sediments and in open boreholes in the UCA. Some boreholes extend into an underlying Paleozoic carbonate sequence. Shallow well hydrographs show no obvious long term trends but do exhibit variations on the order of three to four years that are correlated with changes in annual temperature and precipitation at lags up to 24 months. Trends observed in deeper wells appear to be largely related to ground water usage patterns and show little correlation with climate over the past 35 years. Stepwise multiple regression modeled average annual hydraulic head in the shallow wells as a function of regional temperature, precipitation, and tree ring variables. Estimated hydraulic heads had a slightly greater range prior to the 1960s, most prominently during an interval of lowered ground water levels between 1930 and 1942. Regression results demonstrate that moisture sensitive tree ring data are viable predictors of past ground water levels and may be useful for studies of aquifers in regions that lack long, high quality precipitation records.     

A Decision‐Analytic Approach to Managing Climate Risks: Application to the Upper Great Lakes1

Brown, Casey, William Werick, Wendy Leger, and David Fay, 2011. A Decision‐Analytic Approach to Managing Climate Risks: Application to the Upper Great Lakes. Journal of the American Water Resources Association (JAWRA) 47(3):524‐534. DOI: 10.1111/j.1752‐1688.2011.00552.x Abstract: In this paper, we present a risk analysis and management process designed for use in water resources planning and management under climate change. The process incorporates climate information through a method called decision‐scaling, whereby information related to climate projections is tailored for use in a decision‐analytic framework. The climate risk management process begins with the identification of vulnerabilities by asking stakeholders and resource experts what water conditions they could cope with and which would require substantial policy or investment shifts. The identified vulnerabilities and thresholds are formalized with a water resources systems model that relates changes in the physical climate conditions to the performance metrics corresponding to vulnerabilities. The irreducible uncertainty of climate change projections is addressed through a dynamic management plan embedded within an adaptive management process. Implementation of the process is described as applied in the ongoing International Upper Great Lakes Study.     

Water quality modeling of fertilizer management impacts on nitrate losses in tile drains at the field scale

Nitrate losses from subsurface tile drained row cropland in the Upper Midwest U.S. contribute to hypoxia in the Gulf of Mexico. Strategies are needed to reduce nitrate losses to the Mississippi River. This paper evaluates the effect of fertilizer rate and timing on nitrate losses in two (East and West) commercial row crop fields located in south-central Minnesota. The Agricultural Drainage and Pesticide Transport (ADAPT) model was calibrated and validated for monthly subsurface tile drain flow and nitrate losses for a period of 1999-2003. Good agreement was found between observed and predicted tile drain flow and nitrate losses during the calibration period, with Nash-Sutcliffe modeling efficiencies of 0.75 and 0.56, respectively. Better agreements were observed for the validation period. The calibrated model was then used to evaluate the effects of rate and timing of fertilizer application on nitrate losses with a 50-yr climatic record (1954-2003). Significant reductions in nitrate losses were predicted by reducing fertilizer application rates and changing timing. A 13% reduction in nitrate losses was predicted when fall fertilizer application rate was reduced from 180 to 123 kg/ha. A further 9% reduction in nitrate losses can be achieved when switching from fall to spring application. Larger reductions in nitrate losses would require changes in fertilizer rate and timing, as well as other practices such as changing tile drain spacings and/or depths, fall cover cropping, or conversion of crop land to pasture.     

THE HUDSON BAY AIR MASS TYPE–SOME CLIMATOLOGICAL IMPLICATIONS

A substantial percentage of days with below normal temperatures in central Illinois during May and June (1956-1965) appear to be associated with polar air masses which traverse the Hudson Bay area before entering the Midwest. January departures, in contrast, are related to polar air masses that enter the United States near the Mackenzie River in western Canada. The general influences of the Hudson Bay area on climate are discussed.     

Modeling Climate Change Impacts on Hydrology and Nutrient Loading in the Upper Assiniboine Catchment1

Shrestha, Rajesh R., Yonas B. Dibike, and Terry D. Prowse, 2011. Modeling Climate Change Impacts on Hydrology and Nutrient Loading in the Upper Assiniboine Catchment. Journal of the American Water Resources Association (JAWRA) 48(1): 74‐89. DOI: 10.1111/j.1752‐1688.2011.00592.x Abstract: This paper presents a modeling study on climate‐induced changes in hydrologic and nutrient fluxes in the Upper Assiniboine catchment, located in the Lake Winnipeg watershed. The hydrologic and agricultural chemical yield model, Soil and Water Assessment Tool (SWAT) was employed to model a 21‐year baseline (1980‐2000) and future (2042‐2062) periods with model forcings for future climates derived from three regional climate models (RCMs) and their ensemble means. The modeled future scenarios reveal that potential future changes in the climatic regime are likely to modify considerably hydrologic and nutrient fluxes. The effects of future changes in climatic variables, especially precipitation and temperature, are clearly evident in the resulting snowmelt and runoff regimes. The future hydrologic scenarios consistently show earlier onsets of spring snowmelt and discharge peaks, and higher total runoff volumes. The simulated nutrient loads closely match the dynamics of the future runoff for both nitrogen and phosphorus, in terms of earlier timing of peak loads and higher total loads. However, nutrient concentrations could decrease due to the higher rate of runoff increase. Overall, the effects of these changes on the nutrient transport regime need to be considered together with possible future changes in land use, crop type, fertilizer application, and transformation processes in the receiving water bodies.     

Impact of Climate and Land Use Change on Streamflow and Sediment Yield in a Snow‐Dominated Semiarid Mountainous Watershed

This study investigates the impact of climate and land use change on the magnitude and timing of streamflow and sediment yield in a snow‐dominated mountainous watershed in Salt Lake County, Utah using a scenario approach and the Hydrological Simulation Program — FORTRAN model for the 2040s (year 2035–2044) and 2090s (year 2085–2094). The climate scenarios were statistically and dynamically downscaled from global climate models. Land use and land cover (LULC) changes were estimated in two ways — from a regional planning scenario and from a deterministic model. Results indicate the mean daily streamflow in the Jordan River watershed will increase by an amount ranging from 11.2% to 14.5% in the 2040s and from 6.8% to 15.3% in the 2090s. The respective increases in sediment load in the 2040s and 2090s is projected to be 6.7% and 39.7% in the canyons and about 7.4% to 14.2% in the Jordan valley. The historical 50th percentile timing of streamflow and sediment load is projected to be shifted earlier by three to four weeks by mid‐century and four to eight weeks by late‐century. The projected streamflow and sediment load results establish a nonlinear relationship with each other and are highly sensitive to projected climate change. The predicted changes in streamflow and sediment yield will have implications for water supply, flood control and stormwater management.     

DAM‐INDUCED MODIFICATIONS TO UPPER ALLEGHENY RIVER STREAMFLOW PATTERNS AND THEIR BIODIVERSITY IMPLICATIONS1

ABSTRACT: This study evaluates the streamflow characteristics of the upper Allegheny River during the periods preceding (1936 to 1965) and following (1966 to 1997) completion of the Kinzua Dam in northwestern Pennsylvania. Inter‐period trends in seasonal patterns of discharge and peak flow at three downstream sites are compared to those at two upstream sites to determine the influence of this large dam on surface water hydrology. Climatic records indicate that significant changes in annual total and seasonal precipitation occurred over the twentieth century. Increased runoff during the late summer through early winter led to increased discharge both upstream and downstream during these months, while slightly less early‐year rainfall produced minor reductions in spring flood peaks since 1966. The Kinzua Dam significantly enhanced these trends downstream, creating large reductions in peak flow, while greatly augmenting low flow during the growing season. This reduction in streamflow variability, coupled with other dam‐induced changes, has important biodiversity implications. The downstream riparian zone contains numerous threatened/endangered species, many of which are sensitive to the type of habitat modifications produced by the dam. Flood dynamics under the current post‐dam conditions are likely to compound the difficulties of maintaining their long‐term viability.     

An integrated assessment of long-term changes in the hydrology of three lowland rivers in eastern England

The flow records of the Rivers Bure, Nar and Wensum in eastern England have been examined with the aim of identifying long-term changes in flow behaviour relating to variations in rainfall amount, land use, land drainage intensity and water resources use. In the study area, and since 1931, there is no evidence of long-term change in rainfall amount or distribution, on either an annual or seasonal basis. Despite changes in water resources use and catchment characteristics since the beginning of the century, such as the ending of water milling and increased land drainage and arable farming, rainfall-runoff modelling over the period 1964-1992 showed that the relationship between rainfall and runoff has remained essentially unchanged in the three study rivers. A catchment resource model used to 'naturalise' the historic flow records for the period 1971-1992 to account for the net effect of water supply abstractions and discharges revealed that mean river flows have been altered by surface water and groundwater abstractions, although the average losses to mean weekly flows due to net abstractions for all water uses was no greater than 3%. Greater losses occurred during drought periods as a result of increased consumptive use of water for spray irrigation and amounted to a maximum loss of 24% in the Nar catchment. In lowland areas such as eastern England that are prone to summer dry weather and periodic drought conditions, an integrated approach to river basin management, as advocated by the EU Framework Directive, is recommended for future management of surface and groundwater resources for public water supplies, river regulation purposes and industrial and agricultural demands.