The Lake Urmia positioned in a closed basin in north-west Iran, positioned at altitude 1250 m above the sea level, and has been rapidly drying since 1990. The lake water level has declined to 1271.58 m in 2008 from the last highest record 1277.80 m in 1994. The lake water volume has fluctuated during the observation period and shows a drop from of 32 to 14.5 million cubic meters, while the lake salinity has increased from 205 to 338 g/l due to the evaporation and water inflow reduction. In the Lake Urmia basin, there has been an increase in public awareness of the possible environmental threat and the unpleasant socio-economical consequences on the region’s inhabitants.  The main aim of this study is to assess the current water use pattern in the Urmia Lake basin system with emphasis on the agricultural sub-system, and to propose adaptive measures and sustainable water management scenarios. The study shows that the main cause for these changes are the diversion of rivers and streams for agricultural irrigation; agriculture is a sector with one of the highest water demands, and frequent drought in early 2000s exacerbated the situation. In addition, a growing population and the increased development of agricultural land has led to an increase in unsustainable practices which have an unpredictable impact on the Lake Urmia ecosystem. This study investigates sustainable water use strategies for Lake Urmia basin, and considers economic and environmental factors, including the loss of valuable ecosystems that highlights social and ethical issues for the current and coming generations.

ABSTRACT SOIL AND WATER ANALYSIS TECHNIQUES FOR AGRICULTURAL PRODUCTION Maral, Nuh M. Sc., Department of Chemistry Supervisor: Prof. Dr. G. inci G&ouml / kmen May 2010, 108 pages In Turkey, usage of increasing amounts of fertilizers and pesticides by some unconscious farmers cause soil pollution and soil infertility for the crop production. Usage of water in excessive amounts and/or in poor quality for irrigation creates problems during the plant production. So in this study, soil and water samples were analyzed by using simple and reliable techniques for the soil and water quality in laboratories of METU and Soil Fertilizer and Water Resources Central Research Institute Laboratory in Ankara. The soil and water samples were collected using the standard techniques from Ankara, Bolu, &Ccedil / orum and Kirikkale. According to the soil test results, the textures of the soil samples are found as loam and clay loam. The total salt content of the soil samples are between 0.033 &ndash / 0.063 % (w/w), meaning they are low salinity soils (total salt less than 0.15 % w/w). The pH of the soil samples are between 7.86&ndash / 8.15, they are slightly alkaline. The phosphorus concentrations of soil samples are in a range 4.95 to 35.45 P2O5 kg/da. Some of the soil samples have too high phosphorus content (greater than 12 P2O5 kg/da). The potassium content of soil samples are found between 141&ndash / 286 K2O kg/da, so the soil is efficient for crop production. Lime content of the soil samples is between 1.04&ndash / 2.67 % (w/w) CaCO3. It means all of the soil samples are calcareous but it is not too high for the agricultural production. Organic matter content of soil samples are found between 0.83&ndash / 2.04 % (w/w). This means the soils are limited in their organic matter content for the crop production. Analysis of 22 water samples yielded EC values between 0.384 &ndash / 1.875 dS/m. Water samples have moderate to high-salinity (if EC values between 0.205 and 2.250 dS/m), yet these can be used for the irrigation of the crops. pH values of water samples are found between 7.18-8.10, meaning that they are slightly alkaline. Bicarbonate concentrations of 19 of the water samples are greater than 200 mg/L. These waters may not be suitable for irrigation of ornamental plants. All of the water samples, except water samples from G&ouml / lbaSi, have sodium absorption ratio (SAR) values between 1 and 9. Water samples with low SAR values, except water samples from G&ouml / lbaSi, can be used for irrigation of almost all soils with little danger of developing harmful levels of sodium. The Residual Sodium Carbonate (RSC) values of water samples Ankara G&ouml / lbaSi and Sincan-1 are greater than 2.50 meq/L and these water samples are not suitable for the irrigation. RSC values of Etimesgut, Sincan-2 and Kazan water samples are positive and lower than the value 2.00 meq /L. All the other water samples have negative RSC values so they are the safe to use for irrigation. It has been observed that development of practical field analysis techniques for all soil and water quality parameters may be possible with exception of micronutrient determination. For determining soil and water quality parameters in the rural areas there is a need to establish a small laboratory with necessary equipment and apparatus and training one or two farmers. With the experience gained in this study, some of these techniques may be adapted to the rural field applications, so soil and water may be tested by the farmers for better yields.

Thesis (Ph. D. in Economics)--Vanderbilt University, Aug. 2007. / Includes bibliographical references (p. 120-128).

Master's thesis. / Format: PDF. Bibl.

This study describes the effects of climate change on food security in agricultural dependent country,Pakistan. Based on secondary sources of data, the study found out the evidences of climate change and itssevere implications on already inadequate and depleted natural resources of the country. The major effectsof climate change are in terms of rise in temperature, variations in precipitation pattern, increasing glaciermelt,and increasing evaporation and increased irrigation water requirements. In addition, the report focuseson Pakistan’s irrigation structure and existent capacity, irrigation water crisis, trans-boundary waterconflicts (internal and external), food shortage and high inflation rate in food components. This shortage offood is mainly because of low-cropped productivity due to irrigation water crisis. Although the country hasworld’s largest integrated irrigation system, however, the water scarcity has made minds of farmers to shiftcultivation from water intensive crops like rice, wheat, cotton and sugarcane to low water required cropsand vegetables putting pressure on food market. Moreover, the crops yield is also less due to strongevaporation and the severity of temperature during long summer season. The constantly rising temperaturefor over last forty years coupled with variations in rainfall pattern often results into uneven surface wateravailability throughout cropping seasons. Further, extraordinary rise in temperature in mountainous regionof Pakistan, causes extra melting of glaciers along with uneven annual precipitation which frequentlyresults into flash floods with millions of people dislocated and loss of billions of worth in food, standingcrops and infrastructure. Pakistan’s population is increasing with over two percent growth rate; therefore,the chief staple foods like wheat, rice, maize, sugarcane, and vegetables have become out of reach of poorpeople and have severe contingent social and economic implications in terms of further enhancing thevulnerability of poor marginalized segments of society.

Irrigation plays an extremely important role in agriculture but climate change is predicted to modify climate patterns with potentially devastating consequences for irrigation. Potential impacts and adaptations are known, but not how implementation strategies may be implemented at the individual irrigation scheme level. Using a case study approach and qualitative research methods this thesis describes the Bwanje Valley Irrigation Scheme (BVIS), Malawi in order to explain how water is managed. Subsequently, historical adaptations are described in order to draw conclusions concerning the vulnerability of the BVIS under normal and extreme hydrological conditions. The BVIS is vulnerable in all conditions because it utilizes a common pool resource. As water supply decreases, irrigation water management becomes less and less equitable which makes the system extremely sensitive to changes in water supply. Capacity to adapt to climate change is limited to funding provided by external agencies which currently limit adaptations to reactive changes

The Indus Basin Irrigation System (IBIS) irrigates 16 million ha of land in Pakistan. The irrigation water is also used for domestic consumption in rural areas and where the ground water is brackish. Many major cities and towns dispose their untreated wastewater directly into the irrigation canal network, which ultimately has adverse impacts on the downstream water quality. In order to better understand the water quality variations, several parameters were measured along a 45 km long irrigation canal (Hakra-6R) in Punjab, Pakistan during the year 2000. The parameters measured were: biochemical oxygen demand (BOD), nitrate (NO3), ammonia (NH3), Escherichia coli (E.coli), dissolved oxygen (DO), pH, and water temperature. The PC-QUASAR model was used as predictive tool to simulate the water quality concentrations along the downstream locations of Hakra-6R canal. The measured data were used to validate the PC-QUASAR model. The model efficiencies ranged from 0.40 to 0.96 for selected parameters. A sensitivity analysis showed that the nitrification, denitrification, BOD sedimentation, and BOD algae rate were the most sensitive parameters of model performance. The BOD decay and sediment oxygen rates have negligible influence on model output. Water quality analysis showed that irrigation water was highly contaminated regarding microbiological aspects (E.coli ∼ 4000 N/100ml).

<p>This research investigated the nature, source and the spatial variation of the salinity of the water used for irrigation in the urban farming area of Philippi, which lies in the Cape Flats region of the Cape Town Metropolitan Area, South Africa. The irrigation water is mainly drawn from the Cape Flats aquifer, and pumped into ponds for eventual crop irrigation. Water samples were collected in summer and in winter from fifteen selected sites using standard water sampling procedures. Each site consisted of one borehole and one pond. The samples were routinely analyzed for salinity levels, and concentrations of major and minor ions. From the same boreholes and ponds, water was sampled in summer for isotope analysis to assess effects of evaporation on the water quality and salinity. Descriptive statistics were used to display the variation in range of specific ions in order to compare them with the recommended ranges. Geographical Information Systems analysis described the spatial distribution of the salinity across the study area, and hydrogeochemical analysis characterized the various waters and detected similarities between the water samples in the study area and other waters found in the Cape Flats region. In addition, the US salinity diagram classification of irrigation water developed by Richards (1954) was used to assess the current suitability of groundwater and pond water samples collected during the entire sampling period for irrigation activities. The research indicated that the concentrations of some ions such as chloride, nitrate, potassium and sodium exceeded in places in the study area, the target range values set by the Department of Water Affairs and Forestry (DWAF, 1996) and the Food and Agriculture Organization (Ayers and Westcot, 1985). It revealed that borehole and pond water were mostly brackish across the area regarding their total dissolved salts content, and fresh water was only found in the middle part of the study area. The research found that sea water does not intrude into the aquifer of the study area, and the accumulation of salts in groundwater and soil in the study area is mainly due to the agricultural activities and partially due to the natural movement of water through the geological formation of the Cape Flats region. The conceptual model of the occurrence of the salinization process supported these findings. From this investigation it is understood that the groundwater and pond water in the study area were generally suitable for irrigation purposes but they have to be used with caution as the vegetables are classified as sensitive and moderately sensitive to salt according to DWAF Irrigation water guidelines (1996). The quality of these waters was mainly affected by the land use activities.</p>

A field study was conducted for two years in three semi-arid regions of Syria in order to define, under field conditions, the wheat (Triticum aestivum L.) yield response function to irrigation water salinity and to study the process of soil salt accumulation. The three regions experience similar climatic conditions (semi-arid Mediterranean climate) but have different soil textures, varying from sandy loam to clay. The study involved 74 farms all of which had been irrigating for more than 3 years prior to this study, with well water of different salinity values (0.44 to 14.1 dS/m). All of these farms operated with similar cultural practices. / Results indicate that the wheat yield response function to irrigation water salinity differs between the three regions. The irrigation water threshold salinity value beyond which wheat yield started to decline, was found to be 6.5 dS/m, 3.5 dS/m and 1.2 dS/m in the Khabur low plains; Aleppo south plains and Shedadeh area respectively. Wheat was more salt tolerant to irrigation water salinity in sandy loam soils than clay loam soils. The three threshold values obtained in this study are different from the "universal" value of 4 dS/m which is proposed in current literature. The "universal" value was obtained from artificially salinized field plots seeded under non-saline conditions. / In addition, it was found that salt accumulation in the soil profile increases as soil clay content increases. / The results demonstrate the necessity of establishing regional water quality criteria when planning the use of saline water sources for irrigation in semi-arid regions.

Thesis (M.S. - Renewable Natural Resources)--University of Arizona, 1982. / Includes bibliographical references (leaves 72-77).