Assessing the integrated water resources development potential of Wadi systems in Iran and their vulnerability to climate change

Similar to other Middle Eastern countries, Iran is experiencing a serious water crisis. Water resources become increasingly stressed in the Wadi regions of central and eastern Iran. Assessing water resources there is thus essential due to growing water demand and possible effects of future climate change. Due to the lack of readily available surface water resources, different water use systems (WUSs) exist that provide water mainly for drinking, irrigation and further domestic use. In addition, many soil and water conservation measures (SWCMs) have been established to slow down the velocity of water and to increase infiltration and percolation rates. These alter hydrological components in Wadi regions that need to be considered. Such characteristics particularly apply to the Wadi basin Halilrood in central Iran. Halilrood River is the largest river in terms of discharge in the Kerman Province and the major water provider for the downstream Jazmorian wetland. The Soil and Water Assessment Tool (SWAT) is employed to model the hydrological processes of the Wadi. WUSs and SWCMs are implemented into the hydrological model to simulate streamflow and major hydrological components under current and future climate change conditions. Moreover, groundwater sustainability and possible alterations in the ecological flow regime are evaluated by taking both climate change and population growth into account. Results of the SWAT model simulation show that the hydrological processes of the Wadi system are better represented when WUSs and SWCMs are implemented. The improvement in model performance varies for different segments of the hydrograph. Peak and mean flows are simulated more accurately due to the improved depiction of infiltration rates and the slower release of water to the channels. The investigation of hydrological components reveals that the contribution of surface runoff and groundwater flows to the streams decrease in all sub-basins with WUSs. On the contrary, a higher contribution of groundwater to the streams is shown in most sub-basins with SWCMs. In sub-basins with both WUSs and SWCMs, groundwater contribution increases or does not show any change. To assess the impact of climate change on the water resources in the near and far future (2030-2059 and 2070-2099) in comparison to the baseline period (1979-2009), the projections from 11 climate models and two bias correction methods (LS: linear scaling and DM: distribution mapping) for two Representative Concentration Pathways (RCP4.5 and RCP8.5) are used as input data for the calibrated hydrologic model. The results indicate a slight increase of streamflow in winter season for both RCPs and both bias correction methods, due to higher precipitation intensity. Besides that, a shift is simulated in the timing of the seasonal peak-flow. This is due to increases in temperature and changes in the precipitation pattern. The Halilrood Basin is expected to be vulnerable to climate change as different segments of the flow duration curve (FDC) show increasing variability that can also be interpreted as an alteration of the future flood and drought extremes. A decrease for very high and high flows is projected under both RCPs. Climate change is causing a slight increase in evaporation and less available water for infiltration and percolation, which eventually leads to zero contribution of groundwater to the main channel. The impacts of climate change and growing water demand on the sustainability of groundwater use and the hydrologic regime of the Wadi are analyzed by linking the SWAT model results to the Indicators of Hydrologic Alteration (IHA) and the Range of Variability Approach (RVA). An unsustainable water resources situation (groundwater recharge is equal or greater than groundwater Demand) is expected in the future for the vast majority of sub-basins with WUSs. Due to the imbalance between the groundwater recharge under climate change and estimated groundwater demand in the future, a decline of groundwater levels is anticipated for the entire Halilrood Basin. This is not only resulting in unsustainable groundwater use, but also changes the hydrologic regime and poses a significant threat to downstream ecosystems. The presented modeling framework is a useful approach, providing beneficial information on the water resources of Iranian Wadi systems and their vulnerability to climate change and population growth. The results of this research can contribute to long-term planning there, which is required for a sustainable water resources management under changing future conditions

Rainfed agriculture: unlocking the potential

Rainfed farming / Soil degradation / Crop production / Climate change / Irrigation methods / Water harvesting / Yield gap / Models / Supplemental irrigation / Water productivity / Watershed management / India

Cities versus agriculture: revisiting intersectoral water transfers, potential gains and conflicts

Water scarcity / Water demand / Water transfer / Water use / Water supply / Water allocation / Environmental effects / Water market

River Ecological Restoration and Groundwater Artificial Recharge

Three of the eleven papers focused on groundwater recharge and its impacts on the groundwater regime, in which recharge was caused by riverbed leakage from river ecological restoration (artificial water replenishment). The issues of the hydrogeological parameters involved (such as the influence radius) were also reconsidered. Six papers focused on the impact of river ecological replenishment and other human activities on river and watershed ecology, and on groundwater quality and use function. The issues of ecological security at the watershed scale and deterioration of groundwater quality were of particular concern. Two papers focused on water resources carrying capacity and water resources reallocation at the regional scale, in the context of the fact that ecological water demand has been a significant topic of concern. The use of unconventional water resources such as brackish water has been emphasized in the research in this issue

Impacts of Anthropogenic Activities on Watersheds in a Changing Climate

The immediate goal of this Special Issue was the characterization of land uses and occupations (LULC) in watersheds and the assessment of impacts caused by anthropogenic activities. The goal was immediate because the ultimate purpose was to help bring disturbed watersheds to a better condition or a utopian sustainable status. The steps followed to attain this objective included publishing studies on the understanding of factors and variables that control hydrology and water quality changes in response to human activities. Following this first step, the Special Issue selected work that described adaption measures capable of improving the watershed condition (water availability and quality), namely LULC conversions (e.g., monocultures into agro-forestry systems). Concerning the LULC measures, however, efficacy was questioned unless supported by public programs that force consumers to participate in concomitant costs, because conversions may be viewed as an environmental service

Current status and long-term insights into the western Dead Sea groundwater system using multi-sensoral remote sensing

Arid regions, that have a terrestrial share of 30 %, heavily rely on groundwater for do-mestic, industrial and irrigation purposes. The reliance on groundwater has partly turned into a dependency in areas where the increasing population number and the expansion of irrigated agricultural areas demand more groundwater than is naturally replenished. Yet, spatial and temporal information on groundwater are often scarce induced by the facts that groundwater is given a low priority in many national budgets and numerous (semi-) arid regions in the world encompass large and inaccessible areas. Hence, there is an urgent need to provide low-cost alternatives that in parallel cover large spatial and temporal scales to gain information on the groundwater system. Remote sensing holds a tremendous potential to represent this alternative. The main objective of this thesis is the improvement of existing and the development of novel remote sensing applications to infer information on the scarce but indispensable resource groundwater at the example of the Dead Sea. The background of these de-velopments relies mainly on freely available satellite data sets. I investigate 1) the pos-sibility to infer potential groundwater flow-paths from digital elevation models, 2) the applicability of multi-temporal thermal satellite data to identify groundwater discharge locations, 3) the suitability of multi-temporal thermal satellite data to derive information on the long-term groundwater discharge behaviour, and 4) the differences of thermal data in terms of groundwater discharge between coarse-scaled satellite data and fine-scaled airborne data including a discharge quantification approach. 1) I develop a transparent, reproducible and objective semi-automatic approach us-ing a combined linear filtering and object based classification approach that bases on a medium resolution (30 m ground sampling distance) digital elevation model to extract lineaments. I demonstrate that the obtained lineaments have both, a hydrogeological and groundwater significance, that allow the derivation of potential groundwater flow-paths. These flow-paths match results of existing groundwater flow models remarkably well that validate the findings and shows the possibility to infer potential groundwater flow-paths from remote sensing data. 2) Thermal satellite data enable to identify groundwater discharge into open water bodies given a temperature contrast between groundwater and water body. Integrating a series of thermal data from different periods into a multi-temporal analysis accounts for the groundwater discharge intermittency and hence allows obtaining a representa-tive discharge picture. I analyse the constraints that arise with the multi-temporal anal-ysis (2000-2002) and show that ephemeral surface-runoff causes similar thermal anomalies as groundwater. To exclude surface-runoff influenced data I develop an au-tonomously operating method that facilitates the identification. I calculate on the re-maining surface-runoff uninfluenced data series different statistical measures on a per pixel basis to amplify groundwater discharge induced thermal anomalies. The results reveal that the range and standard deviation of the data series perform best in terms of anomaly amplification and spatial correspondence to in-situ determined spring dis-charge locations. I conclude on the reason that both mirror temperature variability that is stabilized and therefore smaller at areas where spatio-temporal constant groundwater discharge occurs. 3) The application of the before developed method on a thermal satellite data set spanning the years 2000 to 2011 enables to localise specific groundwater discharge sites and to semi-quantitatively analyse the temporal variability of the thermal anomalies (termed groundwater affected area - GAA). I identify 37 groundwater discharge sites along the entire Dead Sea coastline that refine the so far coarsely given spring areas to specific locations. All spatially match independent in-situ groundwater discharge observations and additionally indicate 15 so far unreported discharge sites. Comparing the variability of the GAA extents over time to recharge behaviour reveals analogous curve progressions with a time-shift of two years. This observation suggests that the thermally identified GAAs directly display the before only assumed groundwater discharge volume. This finding provides a serious alternative to monitor groundwater discharge over large temporal and spatial scales that is relevant for different scientific communities. From the results I furthermore conclude to observe the before only assumed and modelled groundwater discharge share from flushing of old brines during periods with an above average Dead Sea level drop. This observation implies the need to not only consider discharge from known terrestrial and submarine springs, but also from flushing of old-brines in order to calculate the total Dead Sea water budget. 4) I present a complementary airborne thermal data set recorded in 01/2011 over the north-western part of the Dead Sea coast. The higher spatial resolution allows to refine the satellite-based GAA to 72 specific groundwater discharge sites and even to specify the so far unknown abundance of submarine springs to six sites with a share of <10 % to the total groundwater discharge. A larger contribution stems from newly iden-tified seeping spring type (24 sites) where groundwater emerges diffusively either ter-restrial or submarine close to the land/water interface with a higher share to the total discharge than submarine springs provide. The major groundwater contribution origi-nates from the 42 identified terrestrial springs. For this spring type, I demonstrate that 93 % of the discharge volume can be modelled with a linear ordinary least square re-gression (R2=0.88) based on the thermal plume extents and in-situ measured discharge volumes from the Israel Hydrological Service. This result implies the possibility to determine discharge volumes at unmonitored sites along the Dead Sea coast as well that can provide a complete physically-based picture of groundwater discharge magni-tude to the Dead Sea for the first time.:1 Introduction 1.1 Remote sensing applications on groundwater 1.1.1 Classical aspects 1.1.2 Modern aspects 1.2 Motivation and main objectives 1.3 Why the western catchment of the Dead Sea? 1.4 Overview 2 The western catchment of the Dead Sea 2.1 Geological and Structural Overview 2.2 Groundwater system 2.3 Groundwater inputs 2.4 Dead Sea 3 Groundwater flow-paths 3.1 Prologue 4 Method development for groundwater discharge identification 4.1 Prologue 5 Localisation and temporal variability of groundwater discharge 5.1 Prologue 6 Qualitative and quantitative refinement of groundwater discharge 6.1 Prologue 7 Conclusion and Outlook 7.1 Main results and implications 7.2 Outlook References Appendi

Chapter 4: Water

This chapter assesses observed and projected climate-induced changes in the water cycle, their current impacts and future risks on human and natural systems and the benefits and effectiveness of water-related adaptation efforts now and in the future

Applied Geochemistry with Case Studies on Geological Formations, Exploration Techniques and Environmental Issues

Geochemistry has become an essential subject to understand our origins and face the challenges that humanity will meet in the near future. This book presents several studies that have geochemistry as their central theme, from the description of different geological formations, through its use for the characterization of contaminated sites and their possible impact on ecosystems and human health, as well as the importance of geochemical techniques as a complement to other current scientific disciplines. Through the different chapters, the reader will be able to approach the world of geochemistry in several of its subfields (e.g. environmental, isotope, or biogeochemistry) and learn through practical cases

Governance:Governance Frameworks for Wastewater Management

MVZ specimen catalog numbers and views represented. (XLSX 495 kb