Fresh Water availability and It’s Global challenge

Water is prime natural resources fulfilling our needs in a precisious assets.we must acts to preserve and utilize every drop of water.water resources can be assessed on the basis of surface and subsurface water bodies.Climate change impact on ground Water the impact of climate change on ground water has been studied much less than the impact on surface waters. Ground water reacts to climate change mainly due to change in ground water recharge,but also change in river level in response to increase in mean Temperature,precipitation ,variability and sea level as mean precipitations.Changing land use pattern due to increasing ,urbanization, industrialization and agriculture activities are serious issues that causing increase ground water with drawal resulting in depletion of ground water resources and mining of ground water resources,along with deterioration of water quality.Rainfall is highly irregular and erratic and declining year to year due to change climatic conditions as result of serious deforestation global warming etc.Human health is affected by change in biodiversity and ecosystem.Climate change will affect the quality of drinking water and impact of fresh water availability and impact on public health. About 70% of Earth’s surface is water of which 97.5% is salty water and 2.5% is fresh water. Less than 1% of this 2.5% amount of freshwater is accessible. As sea water rise’s , salt water of ocean in filtrate as coastal fresh water due heavy rainfall and flooding waste more fertilizer and municipal sewage mixed with costal fresh water and change alter into more oxygen dead zone. Weather extreme and climate variability is main driver of food production in recent global challenge. Recent global challenge food security, fresh water availability, increase incidence of extreme high sea level. Loss of agriculture reproduction and increase in food prices and changes in weather patterns and alter availability and quality of water in many part of world. Climate change is an on-going phenomenon. This will inevitably bring about numerous environmental problems, including alterations to the hydrological cycle, which is already heavily influenced by anthropogenic activity.Chemical fertlizer’s has been adversely affecting the flora, fauna as well as soil quality . more ever every year plant pathogen are causing loss of 10 to 20% of agricultural production worldwide. Ground water will be vital to alleviate some of the worst drought situations. flooding and contaiminated water supplies, more intense weather events are likely to increase to risk of infectious disease epidemics and erosion of low-lying and costal land. Climate Chang will affect the quality of drinking Water and impact of fresh water availlablity and impact on public health it’s better to use UV Water purifiers.This paper will explore what climate change. Water is prime natural resources fulfilling our needs in a precisious assets.we must acts to preserve and utilize every drop of water.water resources can be assessed on the basis of surface and subsurface water bodies.Climate change imapact on ground Water the impact of climate change on ground water has been studied much less than the impact on surface waters. Ground water reacts to climate change mainly due to change in ground water recharge,but also change in river level in response to increase in mean Temperature,precipitation ,variability and sea level as mean precipitations.Changing land use pattern due to increasing ,urbanization, industrialization and agriculture activities are serious issues that causing increase ground water with drawal resulting in depletion of ground water resources and mining of ground water resources,along with deterioration of water quality.Rainfall is highly irregular and erratic and declining year to year due to change climatic conditions as result of serious global warming .Impacts of sea level rise on salinity intrusion global climate change has resulted in gradual sea level rise. sea level rise can cause saline water to migrate up stream in estuaries and rivers,thereby threating fresh water habitat and drinking- water supplies.Hydrology all the costal margin; fresh ground water flowing in land areas meets with saline ground water from the ocean. the fresh ground water flows from in land areas towards the coast where elevation and groundwater level are lower because salt water has higher content of dissolved salt and minerals. it denser the fresh water,causing it to have hydraulic head than freshwater. hydraulic head refers to the liquid pressure exerted by water column. the higher pressure density of salt water causes it to move into costal aquifiers in a a wedge shape under the freshwater. the salt water and fresh water meets in a transition zone where mixing occurs through dispersion and diffusion.

Today, groundwater is the source of about one third of global water withdrawals and provides drinking water for a large portion of the global population. In many regions it is subject to stress with respect to both quantity and quality. Hence, it is of utmost importance to improve our knowledge about the impacts of climate change on groundwater. Climate change will affect groundwater recharge, i.e. long-term average renewable groundwater resources, via increases in mean temperature, precipitation variability and sea level, as well as via changes in mean precipitation (increasing in some areas and decreasing in others). Over many areas groundwater recharge is projected to increase in the warming world (though less than river runoff), but many semi-arid areas that suffer from water stress already may face decreased groundwater recharge. The sea level rise that is likely to occur during the 21st century might leave many flat coral islands without a reliable groundwater source. However, in coastal areas with a land surface elevation of a few metres or more, groundwater availability is more strongly impacted by changes in groundwater recharge than sea-level rise. Under climate change, reliable surface water supply is likely to decrease due to increased temporal variations of river flow that are caused by increased precipitation variability and decreased snow/ice storage. Under these circumstances, it might be beneficial to take advantage of the storage capacity of groundwater and increase groundwater withdrawals. However, this option is only sustainable where groundwater withdrawals remain well below groundwater recharge. Groundwater is not likely to ease freshwater stress in those areas where climate change is projected to decrease groundwater recharge (e.g. Northeast Brazil and the Mediterranean basin).

Identifying the dominant effects of climate and land use change on soil water balance in deep loessial vadose zone

Abstract. Groundwater abstraction from coastal aquifers is vulnerable to climate change and sea level rise because both may potentially impact saltwater intrusion and hence groundwater quality depending on the hydrogeological setting. In the present study the impacts of sea level rise and changes in groundwater recharge are quantified for an island located in the Western Baltic Sea. The low-lying central area of the investigated part of the island was extensively drained and reclaimed during the second half of the 19th century by a system of artificial drainage canals that significantly affects the flow dynamics of the area. The drinking water, mainly for summer cottages, is abstracted from 11 wells drilled to a depth of around 20 m into the upper 5–10 m of a confined chalk aquifer, and the total pumping is only 5–6% of the drainage pumping. Increasing chloride concentrations have been observed in several abstraction wells and in some cases the WHO drinking water standard has been exceeded. Using the modeling package MODFLOW/MT3D/SEAWAT the historical, present and future freshwater-sea water distribution is simulated. The model is calibrated against hydraulic head observations and validated against geochemical and geophysical data from new investigation wells, including borehole logs, and from an airborne transient electromagnetic survey. The impact of climate changes on saltwater intrusion is found to be sensitive to the boundary conditions of the investigated system. For the flux-controlled aquifer to the west of the drained area only changes in groundwater recharge impacts the freshwater–sea water interface whereas sea level rise does not result in increasing sea water intrusion. However, on the barrier islands to the east of the reclaimed area, below which the sea is hydraulically connected to the drainage canals, and the boundary of the flow system therefore controlled, the projected changes in sea level, groundwater recharge and stage of the drainage canals all have significant impacts on saltwater intrusion and the chloride concentrations found in abstraction wells.

Water Follies: Groundwater Pumping and the Fate of America's Fresh Waters. Glennon, R. 2002 . Island Press , Washington, D.C . 314 pp. $25.00 . ISBN 1-55963-223-2 . There is something mysterious about groundwater that befuddles some of my brightest colleagues. Surface water is so much easier to comprehend. The presence and behavior of surface water is easily observed, and the environmental and economic benefits of surface water are easily quantified. Yet fresh surface water is a small component of the global water budget, which is composed of 125,000 km3 of fresh surface water and 8,500,000 km3 of fresh groundwater. More important, fresh surface water is an integral part of a hydrological cycle linking the oceans, atmosphere, and fresh surface water and groundwater. The linkages between fresh surface water and groundwater are particularly pronounced; indeed, the distinction between the two often is blurred. Thus, one cannot be altered without concomitantly altering the other. In Water Follies: Groundwater Pumping and the Fate of America's Fresh Waters by Robert Glennon, we finally have a general-interest book that tells us why and that details the consequences. The book begins with a brief introduction to water law wherein the reader is informed that surface water and groundwater are legally unrelated in many states. The reader is then shown that these water laws are at odds with our current scientific understanding through a series of case studies that form the core of the book. The case studies show, for example, that groundwater pumping lowers water tables, which subsequently dewaters rivers and lakes and degrades plant and wildlife habitats. The case studies underscore the great hydrologic, economic, and geopolitical complexity of the problem. I can say this no better than Glennon himself, who concludes a case study of the Upper San Pedro River, Arizona, with the following paragraph ( pp. 68–69 ): The saga of the San Pedro River offers a number of lessons, each of them useful for those trying to protect other rivers and streams. First, population growth is driving the increased demand for groundwater. Real estate developers and local politicians are unreceptive to claims that controls on growth are necessary to protect rivers and streams. It is often said that “the engine of the American economy” is growth, and challengers to this mantra may expect a hostile audience. Second, the complicated nature of hydrology and of capture processes creates a serious information problem. It takes considerable time and resources to document the hydrologic connection between pumping and surface flows. It takes little effort to obfuscate the issue by claiming that the science is uncertain. Truth will eventually win out, as declines in river flows confirm that pumping has caused a reduction in flows. Third, time passes to the disadvantage of the resource. Capture processes may occur over decades and be hidden from view. Each new subdivision and irrigation well places additional stresses on the system and enlists new advocates for permissive pumping rules. As time goes by, it becomes increasingly difficult to reverse direction. The 12 case studies show the breadth of the problem. The reader learns that the problem occurs in urban and rural areas, in the Southwest, where one might expect it, and in the Northeast and Southeast, where one might not expect it. The reader is left with the overall impression that this is a problem that either affects us all now or will affect us all in the near future. Fortunately, the book offers hope in a concluding chapter devoted to proposed reforms. This is an important chapter because it provides a list of eight different avenues for reform that could be implemented individually or in concert, with great benefits. Implementation of these reforms will not be easy but can be accomplished, given enough urgency and activism. I do have criticisms about the organization and content of this book. It would have benefited greatly from a separate chapter devoted to basic hydrologic principles and processes, such as the hydrologic cycle and basic groundwater hydrology. Instead, basic hydrologic principles and processes are woven into the case studies, primarily into the case study on the Santa Cruz River, Arizona. Thus, the case studies are the organizational lynchpins, and the basic hydrologic principles and processes are the details. This, to me, seems backward. As written, the basic hydrologic principles and processes are lost amid the case studies, making it is difficult for one not trained in the hydrologic sciences to apply the information in this book to a particular situation. Regarding content, the book lacks detail on a number of important concepts. The case studies focus on the effects of groundwater pumping on surface water and groundwater in riparian and lacustrine ( lake ) systems. However, there are other equally important effects of groundwater pumping. When water tables decline, deeper wells must be developed. Deeper wells typically produce older, more saline water. This already saline water is made more saline when discharged to the surface and subjected to evapotranspiration. Consequences may include more saline surface waters and farmlands abandoned as a result of salt accumulation. Furthermore, when water tables decline, land may subside tens of meters. This can have catastrophic consequences, particularly in already low-lying areas such as the Texas coastal plain, where waterlogged soils and flooding have been made increasingly worse. Finally, when water tables decline near the coast, salt water can intrude into the aquifer, forever fouling the aquifer for future use. Glennon briefly discusses some of these issues, but I would have preferred more-detailed discussions of these critical concepts. In spite of these criticisms, I highly recommend Water Follies: Groundwater Pumping and the Fate of America's Fresh Waters, particularly to conservation biologists not trained in the hydrologic sciences. Conservation biologists, for good reason, have focused their conservation efforts on habitat loss and fragmentation. This book, however, exposes an important flaw in strict habitat-conservation efforts: the water supporting habitats often travels many tens or hundreds of kilometers, and it is affected in almost unknowable ways by groundwater pumping practices. We simply cannot conserve habitats unless we also conserve water sources, which include groundwater recharge areas and flow paths. If we fail to address the critical issues detailed in this book, then we certainly will fail in many conservation efforts, as our already-stressed water resources are further stressed by future growth and development.

Abstract. Groundwater recharge (GWR) is a strategic hydrologic variable, and its estimate is necessary to implement sustainable groundwater management. This is especially true in a global warming context that highly impacts key winter conditions in cold and humid climates. For this reason, long-term simulations are particularly useful for understanding past changes in GWR associated with changing climatic conditions. However, GWR simulation at the regional scale and for long-term conditions is challenging, especially due to the limited availability of spatially distributed calibration data and due to generally short observed time series. The objective of this study is to demonstrate the relevance of using a water budget model to understand long-term transient and regional-scale GWR in cold and humid climates where groundwater observations are scarce. The HydroBudget model was specifically developed for regional-scale simulations in cold and humid climate conditions. The model uses commonly available data such as runoff curve numbers to describe the study area, precipitation and temperature time series to run the model, and river flow rates and baseflow estimates for its automatic calibration. A typical case study is presented for the southern portion of the Province of Quebec (Canada, 36 000 km2). With the model simultaneously calibrated on 51 gauging stations, the first GWR estimate for the region was simulated between 1961 and 2017 with very little uncertainty (≤ 10 mm/yr). The simulated water budget was divided into 41 % runoff (444 mm/yr), 47 % evapotranspiration (501 mm/yr), and 12 % GWR (139 mm/yr), with preferential GWR periods during spring and winter (44 % and 32 % of the annual GWR, respectively), values that are typical of other cold and humid climates. Snowpack evolution and soil frost were shown to be a key feature for GWR simulation in these environments. One of the contributions of the study was to show that the model sensitivity to its parameters was correlated with the average air temperature, with colder watersheds more sensitive to snow-related parameters than warmer watersheds. Interestingly, the results showed that the significant increase in precipitation and temperature since the early 1960s did not lead to significant changes in the annual GWR but resulted in increased runoff and evapotranspiration. In contrast to previous studies of past GWR trends in cold and humid climates, this work has shown that changes in past climatic conditions have not yet produced significant changes in annual GWR. Because of their relative ease of use, water budget models are a useful approach for scientists, modelers, and stakeholders alike to understand regional-scale groundwater renewal rates in cold and humid climates, especially if they can be easily adapted to specific study needs and environments.

<p>The role that of fresh surface and ground water sources play on the coastal water balance, element balances, and the associated biogeochemical processes is currently a matter of intense debate and investigation. The measures of fresh and saline water mixing in coastal areas have been found to be challenging, however stable water isotopes (O-16, O-17, O-18), in combination with further hydrochemical tracers, provide a valuable tool to identify different sources, that are furthermore linked to different biogeochemical processes, e.g. impacting the benthic and pelagic carbon cycle.</p><p>In the present communication, we report on combined investigations in pore and surface waters of Königshafen Bay (North Frisian island Sylt, Germany), a tidal area in the eastern North Sea. In addition, tidal cycles at the outlet of the bay were sampled. Results are compared to potential surface and subterrestrial fresh water endmembers, open North Sea, submarine groundwater discharge in the backbarrier tidal area of Spiekeroog, as well as the Elbe river estuary. Besides dissolved major and minor elements, the stable water isotope composition is used to characterize the temporal and spatial distribution of different water sources to the bay and the seasonal dynamics in the water column. Porewater gradients indicate different degrees of freshening, locally already in the top 50 cm below the seafloor with spatial heterogeneity. Different fresh water endmembers are indicated both by the water isotope and hydrochemical signatures. It turns that at least two fresh water sources can be identified for sediments under SGD impact, that differ in composition from surface water sources draining into the southern North Sea. Further work is on the way to investigate the dynamics in the (sub)surface fresh water sources for the tidal basin and the link to other geochemical tracers, as well as the coupling to the dissolved carbon system on different temporal and spatial scales.</p><p>  </p><p>The investigations are supported by the DFG-project KiSNet, the BMBF project COOLSTYLE (CARBOSTORE), the DAAD, the DFG project Baltic Transcoast, and Leibniz IOW.</p>

In New Mexico in the arid southwestern United States, groundwater recharge is crucial to sustain groundwater (GW), which is vitally important to life, agriculture, industry, and ecosystems. To better understand the changes in recharge statewide, we explored the changes in groundwater recharge (RE), precipitation (P), surface water inflow (SWin), outflow (SWout), diversions (SWdiv), returns (SWret), and surface water and GW evapotranspiration (SWE and GWET) in five New Mexico counties: Taos, Torrance, Doña Ana, Eddy, and Lea during 1975–2015. The results show that the change‐point of RE was in the 1990s, leading to contrasting tendencies in RE before and after the change‐point with a decreasing rate during the latter one. There was a significant positive relationship between RE and P for Taos. The highest contribution rate (CR) to RE was SWout for Taos, whereas GWET ranked as the top CR for the other counties. Furthermore, the annual CR of GWET to RE increased significantly in all counties except Lea. The above results reveal that P and surface water flows played the dominant role in impacting RE in northern New Mexico where surface water is the primary local water resources, whereas GWET had the highest and increasingly continuous influence in central and southern New Mexico where the surface water is much less than that in northern New Mexico. This study shows that water budgets are important to identify differences in regional hydrological regimes that affect planning to maintain RE to groundwater.

The trace elements Sb, Be, and Tl in ground water and Sb, Be, Co, Mo, and U in surface water are unaffected by contamination. Limited quality control data (blanks) for Li and V in ground water and surface water do not allow for a good assessment on the potential contamination associated with these trace elements. Potential contamination was identified for Al, As, Ba, B, Cd, Cr, Cu, Fe, Pb, Mn, Ni, Se, Ag, Sr, and Zn in ground water and surface water. Evidence of potential contamination was shown for Co, Mo, and U in ground water; potential contamination was shown for T1 in surface water. In comparing the potential contamination for these trace elements with the U.S. Environmental Protection Agency's (USEPA) drinking-water standards, the contamination for most of these trace elements is less than 10 percent of the drinking-water standard; therefore, contamination would have little or no effect when comparing trace element concentrations with the USEPA drinking-water standards. The exceptions are Al, Cd, and possibly Pb in ground water, and As and possibly Pb in surface water. Potential contamination identified for these trace elements is greater than 10 percent of the USEPA drinking-water standard, but affects only 5 percent or less of the As, Cd, and Pb samples. For most trace elements, the level of potential contamination is not large enough to significantly affect the measured concentration of the environmental sample. The exceptions may be Fe in ground water and Al in surface water, which have concentrations for at least 10 percent of the environmental samples that exceeded the USEPA drinking-water standards. Sample variability for some of the trace elements could not be determined because there were either no detected concentrations, or there were less than 10 replicate sets with detected concentrations. These trace elements are Be, Ag, and Tl for ground water and Sb, Be, Cr, Co, Pb, Ag, and Tl for surface water. For most trace elements, sample variability was less than 10 percent, which would have little or no affect on the reported concentrations. The exceptions are Al, Cd, Cu, Pb, Rn (at concentrations less than about 700 picocuries per liter), Se, and Zn in ground water and Cu, Se, and Zn in surface water, all of which have sample variability ranging from 10 to 20 percent. Sample variability should be considered when evaluating the potential error associated with a sample measurement. Collection of additional quality control samples for some of these trace elements to determine bias and variability is probably warranted particularly for those trace elements that the NAWQA Program did not begin sampling until 1998. Results obtained from the analysis of the quality control data can be applied to the interpretation of the environmental data collected from 1991 to 2002 and for water-quality data that are currently being collected as part of the NAWQA Program. More...

Many streams in Western Australia are naturally saline. In others, especiallyin the south-western corner, land-clearance and other human activities inthe catchment have accelerated rates of salinisation of surface andgroundwater. Trends in surface water salinity are well-documented but theextent of penetration of saline stream water into the sediments has beenlittle studied. As many of these streams have porous sandy beds and theirflows may derive from groundwater, hydrologic exchange patterns betweensurface water and subsurface hyporheic water were hypothesised togovern the water chemistry of such rivers. We predicted high rates ofhydraulic conductivity, leading to a close relationship between surface andsubsurface (to a depth of 50 cm) salinity, and to a lesser extent, pH anddissolved oxygen. Where surface and hyporheic water differed in salinity,other chemical differences were hypothesised to be similarly marked,perhaps resulting from disjunct shallow subsurface aquifers. Triplicatewells were sampled from upwelling and downwelling zones of thirteenstreams ranging in salinity from ca. 0.2 to 18 g L−1. Despite theseemingly-porous sandy beds at many sites, subsurface water chemistryonly 20–40 cm below the bed sometimes differed markedly from surfacewater. For example, hyporheic water was only one-fifth the salinity ofsurface water at some saline sites (e.g., the Tone River) or 20 per cent moresaline in streams with fresh surface water (e.g., the Weld River). At somesites of intermediate salinity (e.g., the Warren River), subsurface water wasup to three times fresher than surface or downwelling water. Percentagesaturation of dissolved oxygen in the hyporheic water was consistently low(< 40%) whereas pH was more acidic than surface water, presumably dueto microbial activity. Vertical hydraulic conductivity may be limited bylayers of fine sediments and clays, implying that the meso-scale (1–100 cm)hydrological dynamics within the hyporheic zones of these rivers are morecomplex than their sandy beds would indicate. Assumptions of ecosystemdynamics in saline streams must be tempered by an understanding ofhyporheic salinities as subsurface fresher water may support microbial andfaunal assemblages excluded from the surface benthos by high salinity. Insaline streams, as in fresh ones, the hyporheic zone is an importantcomponent of the stream ecosystem and equally prone to disruption byhuman activities.

Industry, commerce, and public utilities in 1954 withdrew about 1,500 mgd from surfaceand groundwater sources in the New Orleans area. Most of the withdrawal was made from the Mississippi River. However, some withdrawal of surface water was made from Lake Pontchartrain. A large part of the withdrawal from both groundand surface-water sources is available for reuse. Ground-water withdrawal amounts to about 100 mgd and is primarily for industrial and commercial uses. The average flow of the Mississippi River for the 23-year period, 1931 54, amounted to 309,000 mgd, and the approximate average flow of all the tributaries to Lake Pontchartrain is about 4,000 mgd. The flow of the Pearl River, which adjoins the tributary drainage area of Lake Pontchartrain, averages about 8,000 mgd. Total withdrawal of ground and surface waters amounts to less than 3 percent of the recorded minimum flow of the Mississippi River or less than 1 percent of the average flow. Although large quantities of water are always available in the Mississippi River the quality of the water is not suitable for all uses. Streams from the north that drain into Lake$ Maurepas and Pontchartrain, and the aquifers in that area, offer one of the best sources of fresh water in the State. Industry, if located on the northern shores of Lake Maurepas or Lake Pontchartrain near the mouths of these tributaries, would be assured of an ample supply of either ground or surface water of excellent quality. All the tributaries north of Lake Pontchartrain have dry-weather flows which are dependable. The Pearl River above Bogalusa also is a good source of fresh water of excellent quality. At present it serves to dilute the tidal flow of salt water into Lake Pontchartrain through the Rigolets, the principal outlet of the lake. In the area north of Lake Pontchartrain, wells 60 to 2,000 feet deep yield fresh water. There are no known wells tapping sands below 2,000 feet. However, electrical logs of oil-test wells show that fresh water is available to a maximum depth of 3,000 feet. In the area south of Lake Pontchartrain, there is no withdrawal of ground water for public water supplies because of the saline content of the water. Three principal water-bearing sands, the 200foot, 400-foot, and 700-foot sands, are tapped in the New Orleans area south of Lake Pontchartrain for industrial and commercial use. In this area all deeper sands yield salt water. In some areas the 200-foot sand contains saline water of the sodium chloride type. Consequently, this sand is not developed extensively. Water from the 200-foot sand is relatively fresh north of the Mississippi River and becomes increasingly saline to the south and west. The 400-foot sand is the second most highly developed aquifer in the New Orleans industrial district. The aquifer appears to be very prolific, but its full capabilities have not yet been determined. This aquifer yields a highly mineralized sodium chloride water in some areas; however, elsewhere it is a source of large quantities of fresh water. The 700-foot sand is the most continuous freshwater bearing sand in the area and is the principal source of fresh ground water in the New Orleans industrial district. Most of the wells tapping this aquifer yield soft water of the bicarbonate type. In the southern and western parts of the industrial district the water in the 700-foot sand is too mineralized to be suitable, for human consumption.

Introductionin current situation when world is facing massive population, producing enough food and adequate income for people is a big challenge specifically for governors. This challenge gets even harder in recent decades, due to global population growth which was projected to increase to 7.8 billion in 2025. Agriculture as the only industry that has ability to produce food is consuming 90 percent of fresh water globally. Despite of increasing for food demand, appropriate agricultural land and fresh water resources are restricted. To solve this problem, one is to increase water productivity which can be obtain by irrigation. Iran is not only exempted from this situation but also has more critical situation due to its dry climate and inappropriate precipitation distribution spatially and temporally, also uneven distribution of population which is concentrate in small area. The only reasonable solution by considering water resources limitation and also restricted crop area is changing crop pattern to reach maximum or at least same amount of income by using same or less amount of water. The purpose of this study is to assess financial water productivity and optimize farmer’s income by changing in each crop acreage at basin and sub-basin level with no extra groundwater withdrawals, also in order to repair the damages which has enforce to groundwater resources during last decades a scenario of using only 80percent of renewable water were applied and crop area were optimize to provide maximum or same income for farmers. Materials and methodsThe Neyshabour basin is located in northeast of Iran, the total geographical area of basin is 73,000 km2 consisting of 41,000 km2 plain and the rest of basin is mountains. This Basin is a part of Kalshoor catchment that is located in southern part of Binaloud heights and northeast of KavirMarkazi. In this study whole Neyshabour basin were divided into 199 sub-basins based on pervious study.Based on official reports, agriculture consumes around 93.5percent of the groundwater withdrawals in Neyshabour basin and mostly in irrigation fields, surface water resources share in total water resource withdrawals is about 4.2percent, which means that groundwater is a primary source of fresh water for different purposes and surface water has a minor role in providing water supply services in the Neyshabour basin. To determine crop cultivation area, major crops divided into two groups. two winter crops (Wheat and Barley) and two summer crops (Maize and Tomato). To accomplish land classification by using supervised method, a training area is needed, so different farms for each crop were chosen by consulting with official agricultural organization expert and multiple point read on GPS for each crop. The maximum likelihood (MLC) method was selected for the land cover classification. To estimate the amount of precipitation at each 199 sub-basins, 13 station data for precipitation were collected, these stations are including 11 pluviometry stations, one climatology station and one synoptic station. Actual evapotranspiration (ETa) is needed to estimate actual yield (Ya). Surface Energy Balance Algorithm for Land (SEBAL) technique were applied on Landsat 8 OLI images. To calculate actual ETa, the following steps in flowchart were modeled as tool in ArcGIS 10.3 and a spreadsheet file. To estimate actual crop yield, the suggested procedure by FAO-33 and FAO-66 were followed. Financial productivity could be defined in differently according to interest. In this study several of these definition was used. These definitions are Income productivity (IP) and Profit productivity (PP). To optimize crop area, linear programing technique were used. Results and discussionaverage actual evapotranspiration result for each sub-basin are shown in context. In some sub-basins which there were no evapotranspiration are shown in white. And it happens in those sub-basins which assigned as desert in land classification. In figures 8 and 9 minimum amount of income and profit productivity for wheat and barley is negative, this number means in those area the value of precipitation is higher than value of evapotranspiration, so lower part of eq. 21 and 22 would be negative and in result water productivity would be negative. Since most of precipitation occurs during cold season of the year these numbers are expected. Two sub-basins of 43 and 82 has the value of negative, it means in these two sub-basins groundwater are recharging during the year 2014-2015.The maximum value of income and profit productivity belong to wheat and barley which are winter crops and mostly rain fed, so amount applied water would be so low and in result productivity increased. Among the summer crops maize has the most income and profit income which can be interpret due to their growing period and the crop types. Maize has around 110 days to reach to maturity and harvest, on the other hand tomato needs 145 days to harvest. Some plant is C3 and some are C4. C4 plants produce more biomass than C3 crops with same amount of water which leads to more productivity. The results showed that tomato should have the most changes in area reduction (0.2) and maize should have no changes in both scenarios. Crop area should reduce to 66percent of current cultivation area to maintain ground water level and only 6percent reduction in cultivation area would result in 20percent groundwater recharging. Conclusion to save groundwater resources or even retrieve the only water resource, cultivation area must reduce if the crop pattern will not change. In this study only four crops were studied. It seems best solution is to introduce alternative crop.

Sri Lanka’s average annual temperature could rise by 1.0o C to 1.5o C by 2050 even if carbon emission reduction measures are taken as recommended by the Paris Agreement of 2015. Approximately 19 million people live in locations that could become moderate or severe hotspots by 2050 under the carbon-intensive scenario. Several provinces in the country including the Northern Province emerge as hotspots for climate change vulnerability. This paper analyses the resilient capacity of Jaffna Province to climate change challenges. Secondary information taken from government sources supplemented by observations of the researcher are used for this analysis. Jaffna is one of the 25 districts of Sri Lanka and located in the far north of the country in the Northern Province. It has an area of 1,025 square kilometers. The climate is considered to be tropical monsoonal with a seasonal rhythm of rainfall. The temperature ranges from 26o C to 33o C. Annual precipitation ranges from 696 mm to 1,125 mm. The north east monsoon rain (October to January) accounts for more than 90% of the annual rainfall. The peninsula is mostly surrounded by water, connected to the rest of the island by a small strip of land. Its underground water is used for drinking, agriculture and industry. Paddy cultivation is rain fed but only for three months during the North East monsoon period. The unique geomorphological set up in Jaffna peninsula area is characterised by the underlain Miocene limestone formations which are generally 100 to 150 m thick and distinctly bedded, well jointed and highly karstified, thus giving rise to the shallow aquifer of the peninsula which consists of the channels and cavities (karsts) of this Miocene Limestone. The total population of the district is around 600,000. Agriculture and fisheries have been the principal economic activities of the district. Over 60% of the work force in the district depends on agriculture for their livelihood. About 86,000 families are engaged in agriculture while 15,000 families engage in fishing. Agriculture in the district contributes substantially to the GNP of the country. The average land holding area is around 0.5 to 0.75 acres (3,000 m2). Unemployment in the rural areas is 27.9% while in the urban area it is 25.8%. From the meteorological records from 2008 to 2018, it is shown that the annual average rainfall shows a decline from 2015 onwards although a peak of 1800 mm was shown in 2015 causing severe floods in the entire Peninsula (2,247,225 cum). The average annual temperature also showed a peak in 2016 and then showed a declining trend thereafter. The minimum temperature also showed a similar pattern having a peak in 2016 and then a declining thereafter. According to the climate predictions in 2080, Jaffna Peninsula will have an average annual temperature increase between 4.10o C to 4.50o C under very severe climate change scenario. Similarly the change of rainfall will be 0.1% to 20.0% in 2080 (Punyawardene, 2013). The thin fresh water lens over the saline water makes the Peninsula very vulnerable by way of water quality as salt water intrusion can happen if not careful. Already there is a threat from over extraction of water from the tube wells with the influx of population after the war. The existing storm water drainage system in the Jaffna Municipal Council (JMC) is functioning sub optimally due to non maintenance and irrational behaviors of inhabitants who use the drains and ponds as dumping channels of solid waste and waste water. This reduces the ground water recharge which will reduce the fresh water further. In addition to this, due to the discharges of industrial, agricultural and domestic effluents, the water is polluted. The relatively high percentage of families with low incomes (below 5,000 per month), small and medium scale commercial entities show poor environmental consciousness. Poor law enforcement and institutional capacity of the institutions especially JMC makes matters worse thus causing the Peninsula very vulnerable to climate change related disasters. Keywords: Jaffna Peninsula, Climate change, Vulnerability, Resilience, JMC

Severe problems of rising groundwater and secondary soil salinization demand holistic agricultural water management in canal command areas. Drip irrigation with alternate use of fresh and saline waters is an excellent irrigation approach to mitigate salinity stress caused by highly saline ground water and also to avoid soil sodicity hazards from canal water. Therefore, a study on cyclic mode conjunctive use of good quality surface water (SW) and highly saline ground water (GW) having average electric conductivity 0.3 and 7.6 dS m−1, respectively was carried out in wheat with five treatments of drip viz. 1SW1GW (1:1 :: SW:GW), 1SW2GW (1:2 :: SW:GW), 2SW1GW (2:1 :: SW:GW), SW (all SW), GW (all GW), and one treatment of conventional border ­irrigation method (BI). Highest grain yield was observed in SW (2.99 t ha−1) in 2017–2018 and BI (3.83 t ha−1) in 2018–2019 season. However, yield of SW and BI were statistically at par in both seasons. Grain yield of 1SW1GW, in which only 50% freshwater was used was found statistically at par with SW and BI. Physical Water Productivity was highest for SW, amounting 9.34 and 14.13 kg ha−1.mm−1 during 2017–2018 and 2018–2019, respectively. Soil salinity build up was highest for GW and lowest for SW, whereas it was almost similar for BI and 1SW1GW. Thus, 1SW1GW showed added benefits as its grain yield was statistically at par with SW and BI along with 50% fresh water saving over SW and higher water productivity than BI for similar salinity levels.

Climate change potentially causes the extreme hydrologic events which affect the groundwater contamination. Climate change significantly causes changes in surface water levels and quality, and due to the dynamics of surface water-groundwater interactions, there may be "hidden threats" to the quantity and quality of groundwater resources. This review proposes to provide a systematic bibliometric analysis of critical discussions on the link between climate change and groundwater quality in terms of chemical contamination, eutrophication, algal blooms, microbial contamination, and antibiotic resistance, and on strategic adaptation to climate change in terms of integrated groundwater management. One of the potential impacts of climate change on groundwater resources includes enhanced contamination of pollutants resulting from geogenic and anthropogenic sources. However, there has been a greater focus on the quantity and recharge potential of groundwater as impacted by climate change, and little attention has been focused on climate change impacts on groundwater quality parameters in terms of contamination. The majority of the literature focuses on the climate change induced groundwater quantity whereas this review discusses the climate change indicators from groundwater quality point of view rather than quantity. This review demonstrates that the climate-induced rising temperatures will result in increasing the groundwater temperatures approximately 1.5 to 3 degrees by end of this century and significantly impacts the groundwater quality caused by hydrogeochemical reactions. This review also highlights the climate change induced surface runoff patterns combined with wastewater discharge, and the inappropriate disposal of antibiotics causes contamination of groundwater with antibiotic-resistant bacteria, thereby posing significant risks to public health. Future groundwater quality and recharge projections require a multidisciplinary approach that integrates insights from climatology, socioeconomics, agricultural modelling, and soil sciences to comprehensively understand the complex groundwater interactions. It is suggested that further study should be performed to improve our critical understanding of the relationships between groundwater and climate to directly integrate groundwater management. The outcomes will not only contribute directly to the protection of groundwater security but also help indirectly to achieving UN Sustainable Development Goals (SDG) (SDG 6—clean water and sanitation; SDG 13—combating climate change). • High precipitation enhances the risk of microbial contamination in groundwater (GW) • Climate change event can reduce surface runoff by 21% and GW recharge by 38% • Intense wildfire accelerates mineral weathering which can raise the salinity of GW • Increase in temperature led to the changes in the biotic and abiotic processes in GW • Decrease in dissolved oxygen concentration can alter the chemical processes in GW