Into the Ghost-land

This chapter describes the arrival of the Great Arab Revolt Project (GARP) archaeologists at the derelict Hejaz Railway—GARP’s main study area—which snakes across the deserts and wadis of southern Jordan, from the medieval town of Ma’an to the Bedouin settlement of Mudawwara near the border with Saudi Arabia. There was an enchantment of the senses in finding traces of the world’s first global industrialized conflict alongside those of deep prehistory, churned together it seems by the advent of modern guerrilla warfare, where time is built into the relationship between metal and rust. The sand itself has been touched, blown, and sifted by history, from Nabatean spice traders to Hajj pilgrims, from Ottoman Turkish troops to the Bedouin. Each of these experienced the desert in their own way, and like others in distant parts of the world, brought their own magical thinking to bear on their surroundings. Indeed, the empty desert is anything but, and the ruins of the Arab Revolt emerge from it as a unique heritage of the modern world.

‘Little Ice Age’ maxima and glacier retreat in northern Troms and western Finnmark, northern Norway

<p>Glaciers are important indicators of climate change and observations worldwide document increasing rates of mountain glacier recession. Here we present ~200 years of change in mountain glacier extent in northern Troms and western Finnmark. This was achieved through: (1) mapping recent (post-1980s) changes in ice extent from remotely sensed data and (2) lichenometric dating and mapping of major moraine systems within a sub-set of the main study area (the Rotsund Valley). Lichenometric dating reveals that the Little Ice Age (LIA) maximum occurred as early as AD 1814 (±41 years), which is before the early-20th century LIA maximum proposed on the nearby Lyngen Peninsula, but younger than the LIA maximum limits in southern and central Norway (ca. AD 1740-50). Between LIA maximum and AD 1989, the reconstructed glaciers (n = 15) shrank by 3.9 km<sup>2</sup> (39%), with those that shrank by >50% fronted by proglacial lakes. Between AD 1989 and 2018, the total area of glaciers within the study area (n = 219 in AD 1989) shrank by ~35 km<sup>2</sup>. Very small glaciers (<0.5 km<sup>2</sup> in AD 1989) show the highest relative rates of shrinkage, and 90% of mapped glaciers within the study area are <0.5 km<sup>2</sup> as of AD 2018.</p>

Hydrology and Hydraulics of the Lubigi Wetland in Uganda

The Lubigi wetland, which is located in the north-western part of Kampala, receives polluted water from Kampala city and discharges it into Mayanja River. However, there is lack of information and knowledge on the hydrology and hydraulics of the Lubigi wetland, which are important for protection of wetland ecosystems and fulfill the Uganda national policy for the conservation and management of wetland resources. The national policy aims at promoting the conservation of Uganda’s wetlands, in order to sustain their ecological and socio-economic functions for the present and future well- being of all the people of Uganda. Pertinent data collection, field tests and surveys were carried out to gather data necessary for establishing the current status of the hydraulics and hydrology of Lubigi wetland. The results revealed that the Lubigi wetland demonstrates considerable impounding reservoir and flood buffering capacity. This is an important service provided by the wetland, to alleviate possible negative impacts of storms and floods events. The Lubigi wetland total influents and effluents discharges, have mean values of 222,377.60±132,365 m3 /day and 221,356.80±122,256 m3 /d, respectively. The wetland water balance is dominated by the influent discharges which account for 93.21% of the total water influx, and the effluent discharges which account for 97.7% of the total water outflow. The wetland main study area hydraulic residence times, varies between 6.0 hours and 10 days. Hence, the wetland is endowed with abundant water fluxes, water impounding capacity and adequate hydraulic retention times. The volumetric efficiency of the wetland main study area is 63% and 38% during wet season and dry season, respectively. This indicates that on average only about 50% of the volume of the Lubigi wetland main study area is lost through short-circuiting. The dispersion number of the wetland was about 0.01 to 0.03, which indicates that the flow regime through wetland is close to plug flow.

The Fate of Nitrogen and Faecal Coliform in the Lubigi Wetland in Uganda

The capacity of the Lubigi wetland to reduce nitrogen and faecal coliform pollution entering Lake Kyoga in Uganda was investigated. Three transects with 5 sampling points in each, were established in the wetland. Wetland plants samples were collected from the specific locations along the transects, and laboratory tests and analyses were carried out for plants biomass and nitrogen contents determination. Samples of wetland sediments were also collected, and laboratory tests and analyses were done for determination of nitrogen content in the sediments. Wetland water samples were taken from the main wetland inlet and the main outlet from the wetland main study area. At the same time, wetland water pH, dissolved oxygen and temperatures were measured in-situ. Laboratory tests and analyses for ammonia-nitrogen, nitrate-nitrogen, total Kjeldahl nitrogen, total nitrogen and faecal coliforms were carried out on the wetland water samples. The results indicate that the Lubigi wetland received about 16 to 173 mg/l of total nitrogen, largely in form of organic- nitrogen (64.7%) and ammonia-nitrogen (35.2%). Nitrate-nitrogen and Nitrite-nitrite accounted for only 0.1% of the total nitrogen in the inlet. The wetland removed about 24.9% of this nitrogen, which is equivalent to removal of about 1,672 tons of nitrogen annually. About 67.5 gN/m2 and 0.30 gN/kg of dry sediments were sequestered in the wetland plants biomass and the benthic layer respectively. The Lubigi wetland main study area also receives faecal coliform concentrations with the wetland inlet mean value of 653,509 CFU/100ml and its outlet mean value is 218,676 CFU/100ml. These values give a faecal coliform (FC) overall removal efficiency of approximately 66.5%. It was thus concluded that the Lubigi wetland has considerable capacity to buffer and protect Lake Kyoga, by reducing nitrogen and faecal coliform pollution entering the lake.