Desalination by the regional evaporation of brackish water. by Gare Henderson, Director of INDRA research, Gravitational Systems Engineering inc., Fairfax Station, VA  USA Abstract: Introduction: Overview and Assumptions: INDRA represents a new way of looking at hydrological challenges.  In essence the INDRA model is pro-active weather control to achieve useful climate change.  INDRA embodies the idea that regional weather is based upon identifiable forces, and that some of these forces are subject to useful modification, with current knowledge and methods.  INDRA is a regional hydrology modification scheme, based upon the use of specialized seawater conduits.  A regional matrix of seawater conduits will evaporate brackish water in interior regions to increase relative humidity and the frequency of rainfall.  Strategically deployed seawater conduits, fitted with controlled evaporation, atomization, and elevator appliances, will enhance low altitude productive cloud formation.  As the region's hydrological characteristics change over decades, plant transpiration and biodiversity will flourish, adding to the region's hydrological evolution. This paper is written to demonstrate the efficacy of INDRA as a method of desalination.  INDRA based systems are more or less appropriate for a particular region depending upon the hydrological characteristics, and the relative costs of desalination.  However, the assumptions underlying the majority of the research discussed in this paper is based upon the application of an INDRA project to an arid interior region. The objectives of this paper written for presentation to the IDA, are as follows; 1. Elaborate the benefits of hydrological enhancement as a method of desalination. 2. Overview the INDRA project, as a source of potable water 3. Brief on INDRA methods, means, and objectives 4. Review several potential targets for INDRA regional projects 5. Forecast and overview of obstacles to INDRA implementations 6. Call to action INDRA research Primary Discussion: Regional hydrology: Rainfall desalination The hydrological cycle is natural desalination.   1 inch of rain from the average temperate zone rain cloud produces 65 million gallons of desalinated water per square mile, and delivers it often hundreds of miles from brackish sources.   As a desalination method, this translates into $34,900,000 worth of desalinated seawater per 1 inch-mile, (assuming .53 cents per gallon desalination costs 2009).  Transporting that water up-grade from the seaside to the areas where it is needed, for agriculture or city hygiene, doubles the cost of desalination.   Note: Only the costs of building transport facilities are included in the prior calculation.  Regular transport costs, which include system maintenance and energy utilization costs, are estimated to equal the initial costs per 24 months. In areas where there is adequate airborne humidity and systematic passive collection or agricultural application, the direct costs of desalination range from negligible to less than .01 cents per gallon. The quality of naturally desalinated water from brackish sources, assiduously collected, is generally acceptable for the majority of municipal hygiene, agricultural irrigation, and drinking water applications.  In some areas, especially cities, harvested rain or humidity can contain unacceptable levels of local pollution after relatively brief fallow periods.  Dissolved pollution can be mitigated with passive filters and appropriate collection practices.   Airborne water, either as rainwater or extracted humidity, is a reliable local water source in many temperate regions worldwide.  Water harvested from evaporated brackish water can also contain relatively high salt concentrations (TDS less than 10 mg/l, average TDS of 7 mg/l). It is the periodicity and reliability of airborne humidity which has made it an unacceptable source of desalinated water.  Quality of airborne humidity has typically not been an issue. Contemporary human population growth, and supportive agriculture is only casually related to a regions average annual rainfall.  Factors such as tradition, trade, topography, and natural resources are generally more important in guiding the growth of cities. Human population growth drives the need for desalinated water, for drinking, hygiene, and irrigation.   Hydrological patterns are always in flux, as vegetation flourishes or wanes the hydrology of a region will be affected.   Human population growth has already had significant impacts on regional hydrology.  De-forestation, development, flood plain conversion, coast line vegetation modifications, traffic concentration, and industrial activity have all produced documented impacts on regional hydrology.   Human activity can and has modified regional hydrology. INDRA : Regional Hydrology Management INDRA [Interior Natural Desert Reclamation and Afforestation] is a model for active regional hydrology management.  Regional hydrology [non-polar] ranges from the extremes of closed brackish endorheic basins and arid deserts to open fresh water exorheic regions and temperate zone rain forests.  Each of these typical ecosystems supports a particular range of bio-diversity, and each has value in the greater biome.  Human populations, and cultivated regions flourish in a limited portion of this continuum.   Biodiversity, regional weather and global climate are directly linked to the clash of divergent hydrological environments. The fundamental phenomena of wind, rain, temperature, relative humidity, and transitional events, such as storms and droughts are concomitant of hydrological divergence and clash. As agricultural regions and human populations grow increasingly irrespective of established hydrological patterns, the cost effectiveness of active hydrology management is increased.  In many jurisdictions legislative initiatives have been long established to limit water usage during fallow periods.  In other places legislative initiatives range widely.  Rain fall harvesting is restricted in some cases, such as the US state of Colorado, while in numerous areas both residential and commercial harvesting is mandated, and is essential.  Increasingly in drought prone districts, methods such as drip irrigation, municipal desalination and wastewater recycling are mandated. These above mentioned methods are all supply-passive, albeit with significant energy requirements.   Supply passive in the sense that the volume regional humidity is given by natural processes.  Enhanced regional humidity through active humidity generation will increase the effectiveness of established methods, and provide new and exciting potentials.  Evaporation enhancement policies, such as parking lot and sewer designs,  residential and commercial initiatives designed to bypass aquifers, could significantly impact regional humidity for passive collection, rain fall frequency and reduction of seasonal forest fires.   Such policies can accelerate natural hydrological cycles, and periodically shift regional humidity from aquifers to the atmosphere. Rainfall frequency and periodicity are dependent upon a variety of factors.  Adequate humidity, appropriate seed, and wind patterns all contribute to the actual generation of rain.  Of these factors both humidity, and seed can be influenced by legislative policy.  Wind patterns are inter-regional phenomena, which require cooperation between regions to effectively manage. The primary challenge of airborne humidity as a reliable source of desalinated water is humidity volume.  If additional humidity can be added to a region from outside of the normal hydrological cycle, airborne humidity can provide a reliable source of potable water.   INDRA: Method, Means, and Objectives: The INDRA plan involves the development of specialized evaporation conduits, which transport, and strategically evaporate brackish water from a convenient source to an arid region.  Transport methods are conventional pre-cast concrete pipelines for long distance transport.   Transport energy sources will vary with each project, with focus on green or renewable sources, and gravity. Most energy requirements will be to move water up-grade to overcome the natural barriers which are common to arid regions.   Once the water has been transported to the targeted region it is released in specialized evaporation channels.   Evaporation channels are controlled depth and wide expanse to maximize natural evaporation.  The channels are fitted with various appliances to assist in evaporation via increased turbulence, solar heating, misting, and wind redirection.  The channels are also fitted with mist elevation appliances, such as steerable wind deflectors and wind powered fans.  Riparian zones, of salt tolerant plants and trees such as mangroves, are maintained parallel to the evaporation channels.  The riparian zones are crucial for evaporation and to retain and enhance regional biodiversity. INDRA proposes a solution that for approximately $1 million USD per mile, initial investment, can produce sufficient rainfall (TDS 10-7 mg/l) for municipal hygiene and agricultural irrigation miles away from a brackish source.  We estimate that a fully functional INDRA program can achieve a flow rate of 500 cfs, which will introduce 15-16 billion gallons of regional humidity annually.  This translates to about 1,600 1 inch/square miles of annual rainfall.  The distribution of this rainfall will be determined initially by existing topologies and weather patterns.  As regional hydrology evolves,  especially in combination with other regional INDRA projects, both the periodicity and distribution of rainfall will become increasingly predictable. Consequently, if only 5% of this INDRA inducted humidity could be productively harvested, the desalination costs would be in a project with $50 million in annual maintenance/energy costs (approximately 100 mile transit up-grade), less than 1 cent per gallon.  In agricultural regions the productive usage would be as high as 30%, and reduce the desalination costs respectively. Cost Analysis: Potential INDRA Projects: Here are a few potential projects with estimated costs.  In each case the INDRA hypothesis, is that the targeted region will see a gradual change in its natural hydrology.  Within the first 2-3 years, native species, both plant and animal,  will begin to flourish significantly.  Within 5-6 years agricultural acreage will become more productive.  Within 10-15 years regional hydrology, including aquifers, and plant transpiration will have been sufficiently modified, that INDRA inflows can be significantly reduced to maintenance levels. - Mecca, Saudi Arabia from the red Sea:100 million initial investment, 50 million USD annual - Phoenix, AZ from the Gulf of California: initial investment of $250 million, $125 million annual maintenance To calculate the costs for a potential region, our research shows that an initial investment in 2011 USD is 1 million per mile.  Maintenance and energy costs for operation will be approximately 50% of the initial development costs.  These calculations are based upon a maximum elevation of 500 feet above the source.  While the maintenance costs and energy calculations assume combined wind and solar energy.  We estimate that the annual energy costs can be reduced by 40-60% if the INDRA conduits are built parallel to a motorway, and energy harvested from the movement of traffic is utilized for both water transport and elevation. INDRA is the systematic generation of productive rain clouds via long distance up-drafted evaporation of brackish water, and enhanced transpiration.   Transport is primarily via evaporation reducing water transport up-grade, and distribution,  costs significantly. INDRA Project Historic Rationale: While productive cloud formation has long been the acknowledged as the most cost effective means of brackish water desalination, it has proven an elusive goal.  However, there are many documented examples of rainfall levels or frequency being influenced by human activity.  Bell et. al 2006 determined a strong correlation between pollution level created by automotive traffic, and rainfall patterns and intensity.  While particulate induced cloud formation is typical during forest fires.  While clouds formed as a result of forest fire particulates are rarely productive, this is in part due to the low humidity which is concomitant to forest fire generation.  Other sources of particulate production, such as open pit mining, are although undocumented, likely to stimulate cloud formation as well.   Many areas where productive clouds are most desirable, such as desert or other arid regions, also produce high levels of particulate and yet due to the humidity insufficient for productive cloud formation, do not stimulate productive cloud formation. Evaporation of brackish water as advocated by INDRA, will produce additional side-effects, some definite and appropriate, while others are more speculative.  Evaporation of brackish water generates significant sea salt residues at the point of evaporation.  This effect is positive in many cases, as the absence of locally derived salts is an impediment to agriculture (Salt Institute W. H. Elmer), food preservation, ice mitigation, and regular culinary uses.  Wholesale evaporation will also increase the relative humidity of the area, with concomitant affects on regional vegetation.   While the literature is ambivalent on the overall effects of increased soil or atmospheric humidity, the relationship between temperate zone vegetation volume, variety, and viability and atmospheric and soil humidity, as compared with arid regions, makes higher humidity levels clearly beneficial.    The most significant benefits of INDRA projects in aggregate, will according to accepted weather generation models be both the mitigation of regional weather spikes, and eventually regional climate. The potential impacts of hydrological normalization must be accessed relative to bio-diversity, climate change, planetary mass distribution, as well as potential impacts on human population growth and density. Research Perspectives: Significant data exists to substantiate the potentials of INDRA methods for the increase of regional humidity.  However, weather and climate are extremely dynamic and current modeling systems can only embrace small portions of the potential datasets.  The fundamental hypothesis of INDRA is that through the strategic evaporation of brackish water a regions hydrology can be shifted over a relatively short period of time.   This hypothesis is both refutable via modeling, or pilot projects.   The costs are based upon substantial historical data, the benefits are yet to be proven. This paper presented to the IDA in 2011 is a call to action, a call to research.  The investments required are insignificant for the modeling and analysis necessary to support or refute the INDRA hypothesis for a particular region.  Existing historical data when subjected to deep analytics, can lead the way to feasibility studies, and eventually pilot projects.  Pilot projects can be generated as adjunct to on-going road building projects.    In this era of climate instability the need for INDRA or other weather control projects is not casual, it is essential.  While many methods of climate modification are being proposed, INDRA represents a long term solution to a myriad of pressing issues.