Impact of Climate Change on Groundwater Resources: An Example from Cross River State, Southeastern Nigeria

Abstract

This paper presents least square equations for predicting some groundwater physical properties (static water level, total dissolved solids, groundwater temperature) in Cross River State, based on some climatic parameters (rain amount, air temperature). This was to assess the impact of future climate variability on the quantity and quality of groundwater in the study area. The results showed that irrespective of the geologic units and seasons, the static water level (SWL), groundwater temperature (GWT), pH and dissolved oxygen (DO) were in stable state conditions based on low standard deviation (SD) values. Secondly, in all the locations occupied, the amount of rainfall (RA) and air temperature (AT) showed significant correlations with SWL, GWT, pH, electrical conductivity (EC) and total dissolved solids (TDS). Predictive equations using climatic change indicators (RA, AT) and groundwater physical properties (SWL, GWT, TDS) were developed and used as a tool for monitoring the change in groundwater quantity and quality due to climate change. The fluctuations observed in groundwater properties (SWL, GWT) for the study period are attributed to the amount of rainfall and air temperature. The variation in TDS is due more to the influence of seawater and brine intrusion. The effect of geology was more or less insignificant. Hence generally, irrespective of the geology, with known amount of precipitation and air temperature, future changes in SWL, TDS and GWT can be predicted at least for limited management and environmental decisions in the study area.