A SPATIAL STORY OF DESTRUCTION AND RESTORATION: AL HAWIZEH MARSH, IRAQ

The al Hawizeh Marsh of southern Iraq is one of three marshes belonging to the semi-arid Tigris-Euphrates alluvial salt marsh ecoregion. This extensively freshwater wetland is the only natural marsh remaining in this ecoregion following the intentional environmental degradation imposed by the Saddam Hussein regime by the 1990s. As a result, these once highly biodiverse wetlands became wastelands. With the removal of Saddam Hussein in 2003, Iraqis destroyed the embankments on the rivers, allowing water to flow freely back into the marshes. Thus, this project aimed to evaluate, analyze, and visualize the change the al Hawizeh Marsh due to anthropogenic environmental degradation. Geographic information systems (GIS) was utilized to map and analyze changes in land cover change type, vegetation (NDVI), water (MNDWI), soil moisture (SMMI), soil salinity (SI), and land surface temperatures (LST) from 2000 (pre-flooding) to 2019 (post-flooding). This spatial analysis resulted in overall increases in water, vegetation, soil moisture, soil salinity and LST while the marsh itself yielded decreases in soil moisture, soil salinity, and LST. A random forest statistical analysis was performed to evaluate which variables resulted in the greatest change seen within the al Hawizeh Marsh. Unsurprisingly, water was the most crucial factor responsible for marsh’s change from 2000 to 2019. The second and third important change factors included soil moisture content and LST. These results only tell one side of the story; they are not indictive of on ground marsh health. Thus, it is imperative that Iraq implements impactful conservation efforts to promote the restoration and rehabilitation of this critically important and fragile ecosystem

Geomorphology of the lower Mesopotamian plain at Tell Zurghul archaeological site

The landscape of the Lower Mesopotamia Plain (LMP) has been moulded by water-related processes, consequently, its Holocene geomorphic evolution has been strictly connected to the fluvial process and the anthropogenic water management since 8000 BC. About 6000 years ago, during the maximum marine ingression, the modern cities of Nasiriyah and Al-Amara were close to the Persian Gulf shoreline. Successively, the Tigris and Euphrates developed two wide delta systems, that prograded south-eastward developing a complex fluvial network. Remote sensing investigations over the LMP using satellite imagery and topographic analysis revealed the surficial expression of deltaic bodies with a lobate planform and several terminal distributary channels (TDCs), classifiable as tidal-influenced river-dominated deltas. Tell Zurghul archaeological site, belonging to the ancient State of Lagash, expanded in the western part of the recognized TDC during the Mid- and Late Holocene. Indeed, the occurrence of a divergent multi-channel system supplied water for the early civilizations, which improved the water management and prevented floods through a canals network. Therefore, the multi-sensor remote sensing approach over an area of 2850 km2 allowed us to recognize several fluvial landforms, both still active and relict, attributable to the Holocene riverscape of the LMP, as well as anthropogenic features and aeolian deposits. The Main map is a geomorphological map at the scale of 1:120,000 centred on Tell Zurghul, focusing on the geometry, spatial distribution, and state of activity of erosional and constructional landforms

Reconstructing landscape evolution in the Lower Khuzestan plain (SW Iran): integrating imagery, historical and sedimentary archives

During the late Holocene, an avulsion-controlled Karun megafan developed in the Lower Khuzestan plain. Based on the interpretation of satellite data, at least three different Karun channels were detected. A chronological framework is provided by archaeological sites and textual sources. The presence of extensive irrigation systems highlights the important role of human activity in the development of the plain. In addition, there is clear evidence of human actions (construction and destruction of dams) which caused repeated avulsions in the lower reaches of the present-day Karun. Similar impacts may have contributed to other channel shifts in historical times

Characterizing Surface Temperature and Clarity of Kuwait's Seawaters Using Remotely Sensed Measurements and GIS Analyses

Kuwait sea surface temperature (SST) and water clarity are important water characteristics that influence the entire Kuwait coastal ecosystem. The aim of this project was to study the spatial and temporal distributions of Kuwait SST using MODIS images (January 2003 - July 2007), and Kuwait Secchi Disk Depth (SDD), a water clarity measure, using SeaWiFS and MODIS data (November 1998 - October 2004 and January 2003 - June 2007, respectively). MODIS SST images showed a significant relationship with in situ SST data (r2= 0.98). Also, the semi-analytical diffuse light attenuation coefficient at 490 nm, Kd(490), and 488 nm, Kd(488), of SeaWiFS and MODIS, respectively, showed a significant relationship with in situ SDD (r2= 0.67 and r2= 0.68, respectively). The SeaWiFS and MODIS data provided a comprehensive view of the studied seawater characteristics that improved their overall estimation within Kuwait's waters

Assessment of Soil and Water Properties in the Central Marshes Southern Iraq

The Central Marshes are one of southern Iraq's most important wetlands and ecosystems. A study on evaluating soil quality and water quality in terms of chemical properties at certain sites in the southern Iraqi Central Marshes has been conducted to investigate their types and suitability for enhancing the agricultural reality of most field crops. Soil and water samples were collected from 15 sites and transferred to the laboratory. In the lab, the following parameters were determined: electrical conductivity (EC), total dissolved salts (TDS), organic materials (OM), pH, gypsum, and total sulfate content (SO3). The tests conducted on the samples indicated that it could be said that the soil of the Central Marshes is dark blackish-gray silty clay or clayey silt soil and revealed that most of the southern marshlands are suitable for planting different crops. Analysis of the results may have a role in designing and planning upcoming projects such as construction and agriculture, which would have to enlighten the decision maker

Evaluation of Water Resources and Hydraulic Influences in the Restoration of the Western Part of the Mesopotamian Marshlands

The purpose of this study is to assess the water resources and water conveyance system of the western part of the Mesopotamian marshes (Al-Hammar marsh) as well as develop a water conveyance system to distribute water throughout the western Al-Hammar marsh. These processes are significant to identify the current restoration problems and help to create restoration strategies for the marsh. Also, proper management strategy to the Al-Hammar marsh is necessary to preserve the marsh ecosystem, irrigate lands, and provide domestic necessities in the villages. The overall project is divided into three main chapters which address the current ecological and hydrological issues in the western Al-Hammar marsh. Chapter 1 assesses the water used in the restoration of the western Al-Hammar after 2003. Chapter 1 also provides updated calculations concerning the water balance and the water needed for the planned restoration which promotes more efficient water management for the marsh. Chapter 2 looks at the current condition of the water conveyance system in the western Al-Hammar in order to identify its problems, such as water loss, hydraulic problems, and inefficiency. Creating a high efficiency distribution system for the water supply will increase the rate of inundation and promote better management of surface water resources as well as obtain benefits for agricultural irrigation. Chapter 3 discusses how the restoration could be improved with current available surface water resources using multiple feeding points instead several feeder canals, which improves the health of the marsh and rehabilitate the area. The results of the water balance have showed a deficit in water supplied to the marsh, even using the drainage water from the Main Outfall Drain (MOD), due to the high evapotranspiration (ET) and limited surface water resources, which do not have a constant flow to the marsh. The feeder canals are not efficient enough to supply water for both irrigation and restoration purposes in their current condition. Furthermore, they have many issues, including operation problems, insufficient maintenance, and water losses. Improving the feeder canals by creating a lined network of irrigation canals serve both the farmland and increase the restoration of the marsh

Remote sensing applications for the assessment of the geomorphic response of fluvial systems to the Holocene Climate Changes

The general goal of this thesis is the identification and description of the geomorphological responses of the fluvial system to the Holocene Climate Changes, proposing a multi-sensor remote sensing approach. In particular, the specific aim of this work is the improvement of the present knowledge on the Holocene and historical morphodynamics of the Lower Mesopotamian waterscape, especially on the paleo-hydrology of the ancient Tigris-Euphrates fluvial system, focusing on the specific process in the dynamics of the waterscapes which plays a key role in the drainage network evolution in lowland areas. Crevasse splays represent significant geomorphological features for understanding the fluvial morphodynamics in lowland areas where avulsion processes prevail. The southern Mesopotamian Plain is the area where the ancient State of Lagash developed between the prehistoric Ubaid Period (c. 5200 - c. 3500 BC) and the late Parthian era (247 BC - AD 244), representing an ideal case study, where the Italian Archaeological Mission has been recently carried on extensive field-works at Tell Zurghul archaeological site. Here, an interdisciplinary approach, combining field surveys and geomorphological mapping through remote sensing techniques, has been applied for analyzing the function and role of the waterscape on the early civilization. Indeed, the geomorphological analysis through a remote sensing approach and the archaeological surveys are both essential for the reconstruction of a complex environmental system, where landforms due to different morphogenetic processes occur, related to the presence of a wide fluvial-deltaic paleo-system and early human societies. The main aim of the focus on this archaeological site is to contribute to the reconstruction of the surrounding waterscape and know more about waterscape-human interactions during the Holocene. The question of human-waterscape relationship worldwide has been and still is a central topic in geomorphological, environmental, and archaeological research. During the Holocene, the Tigris-Euphrates river system, in the lower sector of the Mesopotamian Plain (Iraq), has been characterized by complex morphodynamics in response to both climate fluctuations and extensive construction of artificial canals, dug since the first human settlements belonging to the Early River Valley Civilizations. The Lower Mesopotamian Plain (LMP) coincides with the southern Tigris and Euphrates deltaic plain, developed starting since the mid Holocene. During the early Holocene, the sea-level rise caused a general and rapid northward shifting of the Persian Gulf shoreline: the maximum marine ingression reached the area where the present towns of Nasiriyah and Al-Amara are located about 6000 yrs BP; after which the widespread progradation of the Tigris and Euphrates delta system accounted for the southward shoreline regression up to the present position. The development of a typical bird-foot delta guaranteed an amount of water indispensable for agriculture, cattle, settlements, and transport. Indeed, the high mobility of the channels and the frequent occurrence of avulsion processes (i.e., levees break and related crevasse splays formation) are the main features typically connected to a multi-channel system, guarantying the water supply through seasonal floods. In the area, the water management during the mid Holocene, digging an extensive network of canals and building several dams, can either improve the socio-economic conditions of a settlement or cause the end of another one. Within a wide floodplain characterized by very low elevation ranges such as the LMP, a remote sensing, multi-sensor approach is a suitable method for identifying the main geomorphological features related to the fluvial avulsion processes, describing the associated morphogenetic processes. Optical and multispectral Landsat 8 satellite images have been processed for computing NDVI and Clay Ratio indices, as well as to extract the Regions of Interest (ROIs) focused on the main features that made up a crevasse splay (i.e., crevasse channel, crevasse levee and crevasse deposit). The spectral signatures from active and abandoned crevasse splays have been extracted and compared among them, adopting four different methods of Supervised Classification. The analysis of the crevasse splays has been integrated with the investigation of the micro-topography leading to recognize the crevasse channels and levees, the upward convexity of the crevasse deposits and the distal or proximal position of the parent channel; the re-classification of different DEM sources, such as the optical AW3D30 and GDEM2 datasets with ground resolution of 1 arcsec (i.e., 30 m cell-1), leads to highlighting the “above-floodplain” topographic configuration of these landforms. The analysis here performed leads to investigating the entire Lower Mesopotamian Plain through both large and medium scale geomorphological investigation, identifying active and abandoned channels, discerning between active and abandoned avulsion processes and distinguishing crevasse channels, levees, and deposits. In like manner, human features are recognized, allowing the evaluation of human-environmental interactions

Deltas in arid environments

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Day, J., Goodman, R., Chen, Z., Hunter, R., Giosan, L., & Wang, Y. Deltas in arid environments. Water, 13(12), (2021): 1677, https://doi.org/10.3390/w13121677.Due to increasing water use, diversion and salinization, along with subsidence and sea-level rise, deltas in arid regions are shrinking worldwide. Some of the most ecologically important arid deltas include the Colorado, Indus, Nile, and Tigris-Euphrates. The primary stressors vary globally, but these deltas are threatened by increased salinization, water storage and diversion, eutrophication, and wetland loss. In order to make these deltas sustainable over time, some water flow, including seasonal flooding, needs to be re-established. Positive impacts have been seen in the Colorado River delta after flows to the delta were increased. In addition to increasing freshwater flow, collaboration among stakeholders and active management are necessary. For the Nile River, cooperation among different nations in the Nile drainage basin is important. River flow into the Tigris-Euphrates River delta has been affected by politics and civil strife in the Middle East, but some flow has been re-allocated to the delta. Studies commissioned for the Indus River delta recommended re-establishment of some monthly water flow to maintain the river channel and to fight saltwater intrusion. However, accelerating climate impacts, socio-political conflicts, and growing populations suggest a dire future for arid deltas.This research received no external funding