The Influence of Weather and Climate Variability on Groundwater Quality in Zanzibar

Abstract

Climate change and variability have been inducing a broad spectrum of impacts on the environment and natural resources including groundwater resources. The study aimed at assessing the influence of weather, climate variability, and changes on the quality of groundwater resources in Zanzibar. The study used the climate datasets including rainfall (RF), Maximum and Minimum Temperature (T max and T min ), the records acquired from Tanzania Meteorological Authority (TMA) Zanzibar office for 30 and 10 (2010-2019) years periods. Also, the Zanzibar Water Authority (ZAWA) monthly records of Total Dissolved Solids (TDS), Electrical Conductivity (EC), and Ground Water Temperature (GWT) were used. Interpolation techniques were used for controlling outliers and missing datasets. Indeed, correlation, trend, and time series analyses were used to show the relationship between climate and water quality parameters. However, simple statistical analyses including mean, percentage changes, and contributions to the annual and seasonal mean were calculated. Moreover, t and paired t-tests were used to show the significant changes in the mean of the variables for two defined periods of 2011-2015 and 2016-2020 at p ≤ 0.05. Results revealed that seasonal variability of groundwater quality from March to May (MAM) has shown a significant change in trends ranging from 0.1 to 2.8 mm/L/yr, 0.1 to 2.8 μS/cm/yr, and 0.1 to 2.0˚C/yr for TDS, EC, and GWT, respectively. The changes in climate parameters were 0.1 to 2.4 mm/yr, 0.2 to 1.3˚C/yr and 0.1 to 2.5˚C/yr in RF, T max , and T min , respectively. From October to December (OND) changes in groundwater parameters ranged from 0.2 to 2.5 mm/L/yr

Exploring Groundwater Quality Trends in Valliyar Sub-Basin, Kanniyakumari District, India through Advanced Machine Learning Techniques

“…The strong correlation between TDS and EC, along with Cl, suggests that agricultural runoff, which is rich in soluble salts, influences the water quality [29,30]. Weak to moderate correlations between independent variables like temperature, relative humidity, and wind speed with water quality parameters imply that while climatic factors do influence water quality, their impact is overshadowed by agricultural practices [31]. In case of Colachal, the strong positive correlation of EC with various ions (Na, TH, Ca, Cl, Mg, andNO ) reflects the significant influence of seawater intrusion and salinity on water quality, a common issue in coastal areas [32].…”

Influence of Vegetation on the Climate

“…When the organic matter content in the soil exceeds 2%, it plays an important role in determining its spectral properties. When the content is less than 2%, other soil constituents become more influential in its spectral behavior than organic matter [9] [10].…”