Monitoring and Assessment of Surface Water Abstractions for Pasture Irrigation from Landsat Imagery: Bega–Bemboka River,NSW, Australia

Irrigation of pasture forms the greatest single use of irrigation water in Australia yet there has been little monitoring of its spatial extent and water demands across southeast Australian coastal catchments where irrigated dairy farming forms an important rural livelihood. This paper provides an analysis of spatio-temporal patterns in the extent of irrigated pasture in the Bega–Bemboka catchment on the south coast of New South Wales from Landsat imagery, and establishes quantile regression relationships between metered monthly irrigation abstraction volumes, evaporation and rainfall. Over the metering period (2000–2007), annual water usage averages 4.8 ML ha^− 1 year^− 1, with January being the month of highest demand with an annualised usage of 10.4 ML ha^− 1 year^− 1. Analysis of Landsat imagery indicates that the spatial extent of irrigated pasture across the catchment has increased from 1266 ha in 1983 to 1842 ha by 2002, together with amalgamation of smaller holdings along less reliable streams into larger parcels along the trunk stream. Quantile regressions to estimate monthly mean and maximum abstraction volumes from monthly evaporation and rainfall data indicate that abstraction volumes are more closely correlated with evaporation. When combined with Landsat analyses of the spatial extent of irrigated areas, such relationships enable estimation of catchment-scale hydrological effects of irrigation abstractions that in turn can help guide regional-scale assessments of the ecological effects and sustainability of spatially and temporally changing irrigation abstraction volumes.     

PCJ River Basins’ Water Availability Caused by Water Diversion Scenarios to Supply Metropolitan Areas of São Paulo

A dynamic systems simulation model of water resources was developed as a tool to help analyze alternatives to water resources management for the Piracicaba, Capivari and Jundiaí River Water Basins (RB-PCJ), and used to run six 50-year simulations from 2004 to 2054. The model estimates water supply and demand, as well as contamination load by several consumers. Six runs were performed using a constant mean precipitation value, changing water supply and demand and different volumes diverted from RB-PCJ to RB-Alto Tietê. For the Business as Usual scenario, the Sustainability Index went from 0.44 in 2004 to 0.20 by 2054. The Water Sustainability Index changed from 74% in 2004 to 131% by 2054. The Falkenmark Index changed from 1,403 m³ person^− 1 year^− 1 in 2004 to 734 m³ person^− 1 year^− 1 by 2054. We concluded that sanitation is one of the major problems for the PCJ River Basins.     

Factors Controlling Gully Advancement and Models Evaluation (Hableh Rood Basin,Iran)

Gully erosion is one of the most complicated and destructive forms of water erosion. In order to prevent this erosion, the important factors controlling gully heads must be understood. This paper examines gully head advancement in the Hableh Rood Basin, Iran by (1) observing gully head advance between 1957 and 2005 using field studies, aerial photography and GIS analysis and: (2) applying and evaluating widely used experimental models including the, Thompson (Trans ASAE 7(1):54–55, 1964), SCS (I) and SCS (II) models, for estimating migrating headcuts over the study period. The results showed that the highest mean gully advancement (0.26 m year^− 1) took place during the 1956–1967 period, with most gullies having lower and steady headcut retreat rates between 1967–2000 (0.21 m year^− 1) and 2000–2005 (0.15 m year^− 1). This suggests that the majority of gullies in the study area were still in the early stages of formation in the first study period and their formation may be linked to land use or climatic changes pre 1956. Analysis of the correlation between environmental characteristics of the study area and gully advancement indicated that the upslope area of head cuts and soluble mineral content of the soil were the two most important factors influencing the spatial and temporal variation of gully longitudinal development. Results of multiple regression revealed that the simple relation including upslope area and soluble minerals can explain 93% of total variance and relatively reflects the effects of runoff and waterfall process for headcut retreat. Application of statistical error analysis to evaluate the four gully advancement models showed that in comparison to other models, the second model of SCS has more reliable results for predicting longitudinal gully advancement in this study area and other similar regions. However, this study indicates that future modelling in the region should consider the role of soil soluble mineral content in predicting gully advancement.     

Soil Erosion Assessment in a Hilly Catchment of North Eastern India Using USLE, GIS and Remote Sensing

In the present study, soil erosion assessment of Dikrong river basin of Arunachal Pradesh (India) was carried out. The river basin was divided into 200 × 200 m grid cells. The Arc Info 7.2 GIS software and RS (ERDAS IMAGINE 8.4 image processing software) provided spatial input data and the USLE was used to predict the spatial distribution of the average annual soil loss on grid basis. The average rainfall erositivity factor (R) for Dikrong river basin was found to be 1,894.6 MJ mm ha⁻¹ h⁻¹ year⁻¹. The soil erodibility factor (K) with a magnitude of 0.055 t ha h ha⁻¹ MJ⁻¹ mm⁻¹ is the highest, with 0.039 t ha h ha⁻¹ MJ⁻¹ mm⁻¹ is the least for the watershed. The highest and lowest value of slope length factor (LS) is 53.5 and 5.39 respectively for the watershed. The highest and lowest values of crop management factor (C) were found out to be 0.004 and 1.0 respectively for the watershed. The highest and lowest value of conservation factor (P) were found to be 1 and 0.28 respectively for the watershed. The average annual soil loss of the Dikrong river basin is 51 t ha⁻¹ year⁻¹. About 25.61% of the watershed area is found out to be under slight erosion class. Areas covered by moderate, high, very high, severe and very severe erosion potential zones are 26.51%, 17.87%, 13.74%, 2.39% and 13.88% respectively. Therefore, these areas need immediate attention from soil conservation point of view.     

Impact of Treated Wastewater Reuse on Agriculture and Aquifer Recharge in a Coastal Area: Korba Case Study

Treated wastewater (TWW) reuse has increasingly been integrated in the planning and development of water resources in Tunisia. The present study aimed the evaluation of the environmental and health impact that would have the reuse of TWW for crops direct irrigation or for the recharge of the local aquifer in Korba (Tunisia). For this purpose water analyses were carried on the TWW intended for the aquifer recharge and on underground water of this area. As for underground water before recharge, no contamination by organic matter or heavy metals is shown but high salinity, nitrate, potassium and chloride concentrations are detected. The bacteriological analyses show the occurrence of faecal streptococcus, thermo-tolerant coliforms, total coliforms and E coli, but absence of salmonella. These results indicate that this water is not suitable for irrigation worse still for drinking purpose. The monitoring of TWW pollutants has demonstrated that oxygen demands (COD and BOD) do not exceed the Tunisian standards for TWW used in agriculture (NT 106.03) except for August when samples reach high values (COD = 139 mg O₂ L^− 1, BOD = 34). It is also the case for temperature, electrical conductivity (EC), salinity and pH. Heavy metal concentrations are under the detection limit. The determination of nutrients shows relatively low concentrations of nitrates, nitrites and orthophosphate (the maxima in mg L^− 1 are respectively 6.6, 5.6 and 0.92) whereas the potassium levels are high (up to 48.8 mg L^− 1) and the ammonia levels very high, reaching 60.6 mg L^− 1. As for bacteriological pollution, while no salmonella and intestinal nematods are detected, high concentrations of total coliforms, thermo-tolerant coliforms, faecal streptococci and E. coli are analysed. Consequently, the better use of TWW in this region would be the use of infiltration basins for the recharge of the deteriorated aquifer by TWW. It would give the opportunity to better the quality of the TWW reaching the groundwater by an additional treatment for bacteriological and suspended solid (TSS) contaminants while being an alternative water for the aquifer recharge and a coastal barrier against seawater intrusion.     

Regional Scale Erosion Assessment of a Sub-tropical Highland Segment in the Western Ghats of Kerala,South India

Revised Universal Soil Loss Equation (RUSLE) has been used in combination with remote sensing and GIS techniques to assess the spatial pattern and annual rate of soil erosion in the Munnar Forest Division in Western Ghats, Kerala, India. The RUSLE takes into account several factors such as rainfall, soil erodibility, slope length and steepness, land cover and erosion control practice for soil erosion prediction. Maximum soil loss of 109.31 t h⁻¹y⁻¹ and the areas with extreme erosion (erosion is higher than 50 t h⁻¹y⁻¹) are confined to 11.46% of the total area, while the area occupied by severe erosion (erosion rate between 25 and 50 t h⁻¹y⁻¹) is 27.53%. The high rate of annual soil erosion is associated with areas of high terrain alteration from the plantation activities and highly elevated hills/plateau margins with steep side slopes. Such an output is highly useful in decision making context to avoid land acquisition in erosion risk areas, or, alternatively, to recommend soil conservation measures to reduce soil loss, if developmental activities are to be continued at high soil erosion risk areas.     

Rainwater Management for Smallholder Irrigation and it’s Impact on Crop Yields in Eastern India

A tank cum open dug well system suitable for plateau region of eastern India has been developed for providing reliable irrigation to croplands. The system comprises of a series of tanks with open dug wells in the recharge zone of the tank that reharvest back the seepage water. Thus, the rainwater remaining in the tank as well as partial seeped water is used for providing round the year full irrigation. This system was evaluated in field in Keonjhar district of Orissa of eastern India with six tanks and five wells in two drainage lines. The total command area of the system of six tanks and five wells in both drainage lines is 23 ha and the total irrigation potential is 44.5 ha. The total cost of the system is US $19,180 making the cost of irrigation resource creation as US $426 per ha which is much less than about $2,220 per ha for major and medium irrigation projects in the last decade of 20th century. The system increased the rice yields from 1.92 t ha^− 1 to a range of 2.25 to 3.8 t ha^− 1 depending upon the package of practices or the amount of inputs. The farmers went for crops in post-monsoon and summer season and the cropping intensity rose to 112% in the first year, 126% in the second year and 132% in the third year. The internal rate of return from the system was 13.4% at the present level of utilization, which is about 2.4% more than the prime-lending rate of Indian banks, and 3.4% more than the lending rate for agricultural purposes.     

Incorporating Virtual Water into Water Management: A British Columbia Example

Virtual water is the water required to produce food or a commodity, and includes rainwater in addition to irrigation and the water required to grow feed in livestock systems. Measuring virtual water is a useful concept in assessing water management as it permits the comparison of crops and livestock from the perspective of embedded water. To evaluate trade-offs in water allocation in countries like Canada with large regional variability in climate, virtual water should be calculated on a watershed scale. Two watersheds in Canada were selected representing wet and dry regions, and virtual water requirements for crop and livestock products were evaluated. For both the Lower Fraser Valley and the Okanagan basins, the results indicate that the most water demanding agricultural activities are livestock and fodder production. In the Lower Fraser basin, berry crops require 32 Mm³ of virtual water per year and have a potential value of $95 million. In contrast, the major fruit crops in the Okanagan require 63 Mm³ of virtual water per year and have a potential value of $95 million. In contrast, the major fruit crops in the Okanagan require 63 Mm³ of virtual water per year and have a potential value of 68 million. Blueberries and grapes which have moderately high virtual water contents have been expanding in the Lower Fraser and Okanagan basins respectively. Water to grow feed dominates overall animal virtual water requirements. Livestock requires nearly 4.5 times more virtual water per year than crops in the Lower Fraser, poultry and dairy having the largest virtual water requirements. In the dry Okanagan basin the total virtual water requirements for crops and livestock are similar. To accommodate future growth, decisions on water management will need to be made, particularly in dry basins such as the Okanagan. Virtual water calculations provide information that can assist decision makers in the strategic choices of reallocation and conservation water use.     

Regional Water Balance and Economic Assessment as Tools for Water Management in Coastal Lebanon

The Lebanese coast is highly subject to seawater intrusion and groundwater deterioration. The study is carried out in Byblos district (Jbeil Caza) 35 km north of Beirut. It aims to investigate the seawater intrusion, to determine the regional water balance of the region and finally to estimate the economic value of that water for agricultural use. The monitoring of the aquifer was achieved through samples from different wells chosen randomly. As for the regional water balance, it was determined with use of a GIS model. The economic evaluation was carried out, using the contingent valuation method to estimate the willingness to pay of farmers to contribute to the improvement of groundwater quality; two alternative scenarios were proposed and compared with the current situation. The annual regional water balance is positive, which means that the region is rich in water. The monitoring results show that the coastal part of the region is slightly contaminated by seawater intrusion due to the excess of pumping from the aquifer. The economic evaluation estimated that farmers would contribute by 102 US$ yr^− 1 for the first proposal and 166.67 US$ yr^− 1 for the second.     

Assessment of the Irrigation Advisory Services’ Recommendations and Farmers’ Irrigation Management: A Case Study in Southern Spain

The Local Irrigation Advisory Services (LIAS) carry out essential work to achieve an efficient use of irrigation water at field and irrigation scheme level, which is crucial in Mediterranean irrigation systems. However, it is unusual to find agronomic and economic assessments of LIAS advice. In this work, the LIAS operating in the Genil–Cabra Irrigation Scheme (southern Spain) was evaluated during the first 5 years of its advice. Acceptance by farmers of the LIAS recommendations was evaluated by using agronomic indicators, such as ARIS (Annual Relative Irrigation Supply). ARIS_LIAS (actual irrigation applied v. recommendation of LIAS) with values ranging from about 0.23 for wheat and sunflower, and 0.94 for maize, also detecting a high variability between farmers, which indicated a scant acceptance of the LIAS recommendations. The economic evaluation of irrigation was made through two economic indicators, Irrigation Water Productivity (IWP) and Irrigation Water Benefit (IWB). IWP values varied significantly between different crops: around 0.23 € m⁻³ in wheat, sunflower and maize, about 0.53 € m⁻³ in cotton and sugar beet, and values higher than 2.0 € m⁻³ in garlic, for optimal irrigation schedules. For IWB, trends were similar, emphasizing the low IWB values in wheat and sunflower (average values of 0.06 and 0.13 € m⁻³, respectively). Consideration of these economic indicators by LIAS could not only help to obtain more suitable and economically profitable irrigation schedules, but also contribute towards a greater acceptance of advisory services by farmers, by shifting the emphasis from maximizing production to maximizing irrigation profitability.     

Lake-Level Change and Water Balance Analysis at Lake Qinghai,West China during Recent Decades

Lake Qinghai, the largest saline lake with an area of 4,260 km² (2000) and average depth of 21 m (1985) in West China, has experienced severe decline in water level in recent decades. This study aimed to investigate water balance of the lake and identify the causes for the decline in lake level. There was a 3.35-m decline in water level with an average decreasing rate of 8.0 cm year⁻¹ between 1959 and 2000. The lake water balance showed that mean annual precipitation between 1959 and 2000 over the lake was 357 ± 10 mm, evaporation was 924 ± 10 mm, surface runoff water inflow was 348 ± 21 mm, groundwater inflow was 138 mm ± 9 and the change in lake level was −80 ± 31 mm. The variation of lake level was highly positively correlated to surface runoff and precipitation and negatively to evaporation, the correlation coefficients were 0.89, 0.81 and −0.66, respectively. Water consumption by human activities accounts for 1% of the evaporation loss of the lake, implying that water consumption by human activities has little effect on lake level decline. Most dramatic decline in lake level occurred in the warm and dry years, and moderate decline in the cold and dry years, and relatively slight decline in the warm and wet years, therefore, the trend of cold/warm and dry climate in recent decades may be the main reasons for the decline in lake level.     

Modeling Water Resources Allocation in a Run-of-the-River Rice Irrigation Scheme

Seventy-five percent of the available water resources in Malaysia are used for rice irrigation. Proper water management must be given due emphasis to effectively manage the water resources. This study analyzed field level practices, which could save irrigation water and thus increase area to be irrigated. The analyses were conducted for both the pre-saturation and normal supply periods using field data collected at the Besut irrigation scheme, Malaysia. Based on field water requirements and available flows at the intake structures, canal simulation was performed using the CanalMan model (Utah State University) together with water balance. The results have shown that pre-saturation should not be done continuously unless flow rates are at least 9.00 and 3.00 m³ s⁻¹ for the Besut and Angga barrages, respectively. If the flow rate falls below these values, then pre-saturation should be done in two phases. However, when the flow rate is between 5.00 and 5.50 m³ s⁻¹ at Besut barrage, pre-saturation should be done in three phases. The simulated schedules were compared with present pre-saturation schedules and it was observed that irrigable area could be increased by 10% than that at present. During the period of normal irrigation supply to the fields, there must be flow rates of at least 5.00 m³ s⁻¹ and 1.50 m³ s⁻¹ at the Besut and Angga barrages, respectively; in order to maintain irrigation supply to the whole irrigation scheme. Otherwise, selective irrigation or irrigation on a rotational basis will have to be enforced.     

An Evaluation of Demand for and Supply of Potable Water in an Urban Centre of Abeokuta and Environs, Southwestern Nigeria

The current and future demand for potable water supply to Abeokuta city and environs in southwestern Nigeria were estimated in this study. The estimated water demands, up to the year 2030, were based on population growth and per capita water consumption. The study also investigated whether the present source of public water supply to the city and environs could meet the estimated demand. The consumption standards of 120 and 60 l per capita per day for urban and semi-urban water supplies respectively, recommended in the Nigerian Water Supply and Sanitation Policy, were used for domestic demand estimates. The institutional, industrial, fire service, horticulture and animal husbandry water requirements were based on reasonable percentages of the total domestic demand. The flow of Ogun River, which is the source of raw water for the Abeokuta Water Supply scheme serving Abeokuta city and environs, was assessed and found sufficient to meet the estimated future potable water requirements of the study area. The study indicated that the estimated current annual potable water demand of Abeokuta city and environs (in 2011) is 5.52 × 10⁷ m³ (1.51 × 10⁵ m³/day) and the projected annual potable water demand for the year 2030 is 7.67 × 10⁷ m³ (2.10 × 10⁵ m³/day). At a design capacity of 1.62 × 10⁵ m³/day, the total water supply from the Abeokuta Water Supply Scheme at full capacity will just be about the total required in 2014. By 2015, the scheme will no longer be adequate to meet the total water required, even if it is run at full capacity. It is therefore imperative that the current scheme is expanded within the next 4 years in order to meet the potable water demand of the intended population.     

Estimation of Crop Coefficient and Evapotranspiration of Wheat (Triticum aestivum) in an Irrigation Command Using Remote Sensing and GIS

Remote sensing and Geographical Information System (GIS) techniques were used to estimate actual crop evapotranspiration of wheat crop grown in Tarafeni South Main Canal (TSMC) irrigation command of West Bengal State in India. The area under wheat crop was clipped from landuse/land cover map generated from Indian Remote Sensing Satellite P6 (IRS P6) image of January, 2004 for winter season 2003–04. The IRS P6 image and four wide field sensor (WiFS) images for different months of winter season were used to determine the Normalized Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) for area under wheat crop. The relationship between vegetation indices and crop coefficients (K_c) of wheat for corresponding months were developed. Based on these developed regression equations crop coefficient maps were generated for each month of wheat crop season. Monthly reference crop evapotranspiration (ETo) was estimated based on FAO-56, Penman–Monteith method. ETo was combined with spatially distributed K_c maps of different months of wheat crop season to generate crop evapotranspiration (ET_c) maps of each month. The crop water demand of wheat estimated using spatially distributed ET_c maps for months of December 2003, January 2004, February 2004, March 2004 (1st Fortnight) and March 2004 (2nd Fortnight) were found to be 3.98, 8.14, 4.66, 2.49, and 1.21 million cubic meter (MCM) respectively. Based on crop evapotranspiration the total crop water demand of wheat crop in irrigation command of TSMC was estimated as 20.48 MCM.     

Quantifying the Poorly Known Role of Groundwater in Agriculture: the Case of Cyprus

Agriculture in the Mediterranean region is constrained by limited water resources and in many countries irrigation demand exceeds the renewable water supply. This paper presents a comprehensive approach to (a) quantify the consumptive green (soil moisture provided by precipitation) and blue (irrigation) water use for crop production, (b) distinguish the contribution of groundwater to irrigation supply and (c) estimate groundwater over-abstraction. A spatiotemporally explicit soil water balance model, based on the FAO-56 dual crop coefficient approach, which includes the computation of evaporation losses of the different irrigation systems, was applied to the 5,760-km² area of the Republic of Cyprus for the agro-meteorological years 1995–2009. The model uses national agricultural statistics, community-level data from the agricultural census and daily data from 34 meteorological stations and 70 precipitation gauges. Groundwater over-abstraction is quantified per groundwater body, based on the sustainable abstraction rates specified in the Cyprus River Basin Management Plan, as prepared for the EU Water Framework Directive. It was found that, on average, total agricultural water use was 506 Mm³/year, of which 62 % is attributed to green water use and 38 % to blue water use. Groundwater contributed, on average, 81 % (151 Mm³/year) to blue water use and exceeded the recommended abstraction rates by 45 % (47 Mm³/year). Even though the irrigated area decreased by 18 % during the 2008 drought year, relative to the wettest year (2003), total blue water use decreased by only 1 %. The limited surface water supply during the driest year resulted in a 37 % increase in groundwater use, relative to the wettest year, and exceeded the sustainable abstraction rate by 53 % (55 Mm³/year). Overall, the model provides objective and quantitative outcomes that can potentially contribute to the improvement of water resource management in Mediterranean environments, in the light of climate change and expected policy reforms.     

Nitrate in the Water-Supply Wells in the Mancha Oriental Hydrogeological System (SE Spain)

This study determines the spatial and temporal distribution of nitrate content within the water-supply wells in the Mancha Oriental System (MOS) for the period 1998–2003 and presents an example of the multiple nitrate pollution sources in the El Salobral–Los Llanos Domain (SLD, southwestern Albacete). The groundwater resources of the MOS are used to maintain approximately 800 km² of irrigated crops and are the sole water supply for a total population of 275,000 inhabitants. The average nitrate content varies from <0.5 mg l^− 1 (detection limit) to 125 mg l^− 1. In some areas of the MOS statistical analyses show a growing tendency between 2001 and 2003. Nitrate content shows a heterogeneous spatial distribution but the highest levels can be associated with large areas of irrigated crops. However, there are also points in which nitrate has been detected in significant quantities which are not found to be spatially linked to this kind of crop. The presence of nitrate in these areas can be explained considering other sources of pollution, such us wastewater, or due to pollutant transport from contaminated areas through groundwater flow in a multiple-layered karstic aquifer. These results lead necessarily to reconsider the agricultural-derived nitrate as the sole source of pollution and to analyze the effectiveness of the current wastewater treatment practices from effluents in the MOS.     

Assessment of Rainwater Availability by Building Type and Water Use Through GIS-based Scenario Analysis

Scenario analysis of rainwater harvesting and utilization (RWHU) was performed considering various non-potable water uses in different building types over a year. Six building types were identified in the study area using GIS data: residential houses, offices, commercial buildings, restaurants, public buildings, and “others”. Rainwater storage capacity was considered as 30 mm rainwater depth. Water demand for each building type was calculated as the sum of the individual water uses for toilet flushing, air conditioning, garden irrigation, and cleaning defined in this study as “miscellaneous usages”. To incorporate water quality considerations, rainwater with suspended solids level of less than 2 mg l⁻¹ was used as the quality criterion. The RWHU scenario was compared with other storage and water use scenarios. This study quantified the rainwater availability throughout a year and its seasonal variation and consumption in each building type. The analysis clarified the effectiveness of rainwater utilization for supplementing existing water resources.     

Groundwater Recharge Assessment for the Kalahari Catchment of North-eastern Namibia and North-western Botswana with a Regional-scale Water Balance Model

Groundwater is the only source of drinking water for the inhabitants of the Kalahari. Thus understanding spatial and temporal variations in groundwater recharge is very important and a regional-scale water balance model has therefore been set up for a 209,149 km² catchment in north-eastern Namibia and north-western Botswana. The model has a spatial resolution of 1.5 × 1.5 km, daily model time-steps, and climatic input parameters for 19 years are used. The distributed, GIS-based, process-oriented, physical water balance model (MODBIL) used in this study considers the major water balance components: precipitation, evapotranspiration, groundwater recharge, and surface runoff/interflow. Mean precipitation for the study area is 409 mm a⁻¹, while mean actual evapotranspiration is 402 mm a⁻¹ and mean groundwater recharge is 8 mm a⁻¹ (2% of mean annual precipitation). The recharge pattern is mainly influenced by the distribution of soil and vegetation units. Groundwater recharge shows a high inter- and intra-annual variability, but not only the sum of annual precipitation is important for the development of groundwater recharge; a large amount of precipitation in a relatively short period is more important. Published independent data from the Kalahari in Namibia, Botswana and the Southern African region under similar climatic conditions are used to verify the modelling results.     

Chemical Evaluation of Ma’an Sewage Effluents and its Reuse in Irrigation Purposes

The present study investigates the chemical composition of Ma’an Wastewater Treatment Plant in south Jordan. Samples of effluent of this plant were collected over 1 year period. All samples were analyzed for pH, conductivity, major ions (Cl⁻, , , , , Na⁺, K⁺, Ca^2 + and Mg^2 +) and trace metals B, Fe, Cu, Zn, Cd and Pb. The pH value ranges from 6.79 to 8.15 with a median value of 7.39 ± 0.32. The water quality was characterized by its high salinity hazard (C3) and low sodium hazard (S1) which can be considered as marginal for human consumption. Moreover, concentrations of trace metals in treated wastewater were found to be low and within guidelines for irrigation water due to low level of industrialization activities in the study area. Generally, the result of this study suggests that the treated wastewater is suitable for irrigational purposes, while these effluents can be considered as possible additional resources for irrigation in Jordan.     

A Stream Water Availability Model of Upper Indus Basin Based on a Topologic Model and Global Climatic Datasets

Integrated water resources management at river basin scales and evaluation of effects of climate change on regional water resources require quantitative estimates of space-time variability of monthly discharges within a river network. This study demonstrates that such estimates, which can be called stream water availability, for regional river basins with meager or nonexistent gauge data, can be obtained by combining continuity models of hydrological processes, flow routing, and topology of the river basin. The hydrologic processes can be adequately modeled using high quality databases of hydrologic significance. A stream water availability model is presented for Upper Indus Basin (UIB) utilizing the most up-to-date datasets for topography, temperature, precipitation, net radiation, land cover, soil type, and digital atlas. Multiple datasets have been evaluated and the ones with best accuracy and temporal coverage have been selected for the final model. Upper Indus River and its major tributaries are highly significant in regional water resources management and geopolitics. However, UIB is a poorly studied and largely ungauged river basin with an area of 265,598 km² and extremely rugged topography. Several factors, the chief ones being the challenging terrain and the trans-boundary nature of the basin, have contributed to this knowledge gap. Hydro-climatologically it is a complex basin with a significant cryospheric component. The spatial and temporal variation of the principal climatic variables, namely precipitation, net radiation, and temperature has been thoroughly accounted for in the development of a stream water availability model based on a process model coupled with a topologic model and a linear reservoir model of river flow routing. Model calculations indicate that there are essentially two hydrologic regimes in UIB. The regime that is truly significant in contributing stream flows, originates from the UIB cryosphere containing outstanding glaciers and snowfields. The other regime, generated from wet precipitation and melt water from seasonal snow covers is insignificant due to high rates of infiltration and evaporation in the semi-desert environment prevailing at elevations below perennial snow and ice covers. In general, the modeled stream flow characteristics match with the sparse discharge measurements that are available. Flow in the Indus considerably increases at its confluence with Shyok River and further downstream where other tributaries form the north join the main stem. At or near the outlet of the basin stream flow can vary from less than 800 m³ s^− 1 in the winter and spring to nearly 8,000 m³ s^− 1 in the peak summer and can persist to over 1,500 m³ s^− 1 in the autumn. The importance of snow and glacial melt in Indus River discharge is apparent and any global or regional climate change affecting the equilibrium line elevation of the snow fields in the Karakoram will have a profound influence on the water availability in the Indus. Estimates are made for per capita water availability in Ladakh and Gilgit-Baltistan territories, controlled by India and Pakistan respectively. Geopolitical significance and climate change effects are discussed briefly.