Browsing by Author "Lalika Makarius C. S."

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Assessing the influence of climate variability and land cover change on water resources in the Wami river catchment, Tanzania
(SPRINGER, 2024-02-13) Lalika Christossy B. C.; Mujahid Aziz Ul Haq; Lalika Makarius C. S.
Understanding the trend, extent, and effect of climate variability and land cover change are globally important for monitor- ing river catchments water resources. Due to the majority of river catchment from developing countries such as Tanzania experiencing insufficient time series data, the long-term ERA5-Land (1960–2021) reanalysis was used to assess the influence of climate variability and land cover change on water resource in the Wami river catchment. The Mann–Kendal–Sneyer test revealed a change that reflects the effect of land cover change on runoff in 1992, hence the mean annual runoff, precipitation, and actual evapotranspiration decreased by 19%, 9.7%, and 8.9%, respectively, while potential evapotranspiration increased by 5% after the change. Budyko decomposition and climate elasticity methods illustrated that variability change caused a notable contribution to the reduction of Wami River runoff. Hydrological sensitivity analysis revealed that variability of climate is a primary factor that reduced runoff with a contribution of 69%, while land cover change is 31%, this illustrates runoff in the Wami river catchment is more vulnerable to climate variability than land cover change by considering that most of the catchment are classified as arid or semi-arid. Thus, our study emphasizes the importance embracing climate adaptation strategies, particularly a nature-based solution (NbS), to ensure the sustainability of water resources within the Wami river catchment.
Hydrological response to land use and land cover change on the slopes of Kilimanjaro and Meru Mountains
(Elsevier B.V., 2022) Mangi Halima O.; Onywere Simon M; Kitur Ester C.; Lalika Makarius C. S.; Chilagane Nyemo A.
Land use and cover change are closely linked to catchment hydrology characteristics. Land uses and cover determine the ability of the catchment to collect, store, and release water. The catchment water storage and flow ability affect the quantity and timing of runoff, soil erosion, and sediment transport downstream. Agriculture on of the major drivers for the changes in water flow pathways, which also causes a catastrophic shift of aquatic ecosys- tems. We assessed the impact of land-use changes on the water flow characteristics in the Upper Pangani Sub catchment using the hydrologic model Soil and Water Assessment Tool (SWAT). Land use and cover changes within the Upper Pangani Sub catchment were ana- lyzed between 1987 and 2017 using QGIS. The result shows that agriculture has expanded from 96,737 ha to 314,871 ha between 1987 and 2017. Bare land and built-up land have gained 14690 ha and 7083 ha respectively during this period. Land-use changes have af- fected the basin’s land cover. Forest has decreased from 196558 ha to 106839 ha between 1987 and 2017. Bush land cover has lost 83445 ha during this period. Bushland cover fall victim to agricultural activities, whereas forest is cleared for logging and fire incidences. Consequently, surface runoff has increased from 60.84 to 73.02 (20.6% increase) between 1987 and 2017. Sediment yield has increase from 6.9 to 12.74 ton/ha (46% increase), and groundwater recharge has decreased from 106.53 to 99.56 (6.5% decrease). It concluded that land cover transformation alters hydrology characteristics of the catchment, resulting to fast surface flow, high rate of soil erosion and low infiltration rate. It is recommended that agro-forestry should be emphasized in the catchment.
Macroinvertebrates as bio Indicators of water quality in Pinyinyi River, Arusha Tanzania
(Scientific Research Publishing Inc, 2023) Omary Rajabu Ramadhani; Lalika Makarius C. S.; Nguvava Mariam; Mgimwa Emmanuel
Rivers are important for aquatic biodiversity. Anthropogenic activities de- grade rivers and decrease their capacity to offer ecosystem services. This study used macroinvertebrates to assess the impact of anthropogenic activities on the Pinyinyi River during dry and wet season. Abundance of macroinverte- brates, average score per taxon and Shannon Weiner Species Diversity Index were used to state the ecological status of Pinyinyi River. Because the abun- dance of macroinvertebrates can be affected by change in water quality, some of the physicochemical parameters were also measured. A macroinvertebrates hand net is used to collect the macroinvertebrates per sampling point. DO, temperature, pH, turbidity and TDS were measured in-situ using HI-9829 Multiparameter and BOD was measured in the laboratory using Oxydirect le- vibond method. A total of 164 macroinvertebrates were collected and identi- fied from Pinyinyi River during dry and wet season. They belong to 13 fami- lies. The most abundant taxa were mosquito larva, Diptera (41.07%) and aq- uatic caterpillar, Lepidoptera (23.21%) during dry season representing about 64.28% of the total macroinvertebrates whereas the least abundant taxa were pouch snail (16.07%) and dragonflies, Odonata (19.64%) during dry season representing about 35.72% of the total macroinvertebrates. The most abun- dant taxa collected during wet season were aquatic earthworm, haplotaxida (19.44%), midges, Diptera (17.59%), black flies, Diptera (15.74%) and creep- ing water bugs, hemiptera (12.96%) whereas the least abundant were pigmy back swimmers, hemiptera (2.78%), snail (3.7%), predacious dividing beetle (4.63%) and coleopteran (4.63%). Average Score per taxon of Pinyinyi River during dry season was 5.25 and 3.6 during wet season. The Shannon Weiner Species Diversity Index was 1.318 during dry season and 2.138 during wet season. Based on the score, Pinyinyi River is moderately polluted during dry season and seriously polluted during wet season. Based on index, Pinyinyi River has low diversity of macroinvertebrates during dry season and highly in diversity of macroinvertebrates during wet season. Moreover, it was found that, agricultural activities, livestock keeping, bathing and washing alter phy- sicochemical parameters of Pinyinyi River and hence change the abundance of macroinvertebrates as well as the quality of water. The study, therefore, recommends that the source of pollutants should be controlled and the river regularly monitored by the relevant authorities