Groundwater sources for the Mataranka Springs (Northern Territory, Australia)

The Mataranka Springs Complex is the headwater of the iconic Roper River of northern Australia. Using environmental tracers measured in springs and nearby boreholes, the origin of groundwater contributing to the springs was evaluated to help assess the impact of proposed groundwater extraction in the Cambrian Limestone Aquifer (CLA) for irrigation agriculture and for hydraulic fracturing in the Beetaloo Sub-basin (an anticipated world-class unconventional gas reserve). Major ions, Sr, 87Sr/86Sr, δ18O-H2O, δ2H-H2O, 3H, 14C-DIC were consistent with regional groundwater from the Daly and Georgina basins of the CLA as the sources of water sustaining the major springs (Rainbow and Bitter) and one of the minor springs (Warloch Pond). However, 3H = 0.34 TU in another minor spring (Fig Tree) indicated an additional contribution from a young (probably local) source. High concentrations of radiogenic 4He (> 10–7 cm3 STP g–1) at Rainbow Spring, Bitter Spring and in nearby groundwater also indicated an input of deeper, older groundwater. The presence of older groundwater within the CLA demonstrates the need for an appropriate baseline characterisation of the vertical exchange of groundwater in Beetaloo Sub-basin ahead of unconventional gas resource development.

Scientific Programming Tools for Water Management

This special issue delivers a platform in which researchers expose intersections between algorithm design, software platforms, and hardware architectures to deal with emerging challenges in the scientific field of management of water and water-dependent resources. Since the call for papers was announced in June 2019, this special issue has received 10 manuscripts. After a rigorous review process, 6 papers have been finally accepted for publication. Published papers deal with groundwater quality monitoring, coastal groundwater-dependent irrigation agriculture, desertification risk, water recovery from tailings, future scenarios of water resources, and vulnerability of coastal aquifers.

Evaluation of FAO-56 procedures for estimating reference evapotranspiration using missing climatic data for a Brazilian tropical savanna

Since the Brazilian Cerrado has been heavily impacted by agricultural activities over the last four to five decades, reference evapotranspiration (ETo) plays a pivotal role in water resources management for irrigation agriculture. The Penman-Monteith (PM) is one of the most accepted models for ETo estimation, but it requires many inputs that are not commonly available. Therefore, assessing the FAO guidelines to compute ETo when meteorological data are missing could lead to a better understanding of how climatic variables are related to water requirements and atmospheric demands for a grass-mixed savanna region and which variable impacts the estimates the most. In this study, ETo was computed from April 2010 to August 2019. We tested twelve different scenarios considering radiation, relative humidity, and/or wind speed as missing climatic data using guidelines given by FAO. When wind speed and/or relative humidity data were the only missing data, the PM method showed the lowest errors in the ETo estimates and correlation coefficient (r) and Willmott’s index of agreement (d) values close to 1.0. When radiation data were missing, computed ETo was overestimated compared to the benchmark. FAO procedures to estimate the net radiation presented good results during the wet season; however, during the dry season, their results were overestimated, especially because the method could not estimate negative Rn. Therefore, we can infer that radiation data have the highest impact on ETo for our study area and also regions with similar conditions and FAO guidelines are not suitable when radiation data are missing.

Introduction

This chapter introduces the themes and arguments of the book. In particular, it explains the benefits of adopting a holistic approach to the history of the river basin that acknowledges its cultural, physical, and biological unity. Treating the Tigris and Euphrates as a continuous whole brings to light the magnitude and significance of river flow that fostered contacts between upstream and downstream regions. Beyond facilitating communication, the twin rivers formed the backbone of the early modern Ottoman economy in the region by supporting complementary subsistence strategies, such as irrigation agriculture, animal husbandry, and wetland exploitation. In addition to the themes and arguments, this chapter offers a brief introduction to the history of the Ottoman Empire and the ecology of the Tigris-Euphrates basin.

Arable Lands

This chapter reconstructs Ottoman irrigation policies in the Tigris-Euphrates alluvial plain. Numerous considerations shaped the Ottoman management of irrigation agriculture in the region. The state’s active support for agricultural development, for instance, was tied to Ottoman concepts of upholding precedent and justice. On the other hand, the ecology and location of the Tigris and Euphrates within the empire restrained whatever agricultural investment the Ottoman state desired to make in the region. Istanbul balanced those cultural, political, and environmental considerations to maintain a hybrid irrigation landscape, largely small in scale and local in character, but with a few giant canals that were administered directly by Ottoman imperial authorities.