Seasonal and Annual Rainfall Variability and Their Impact on Rural Water Supply Services in the Wami River Basin, Tanzania

Abstract

In some parts of Africa, rainfall variability has resulted in widespread droughts and floods, thus posing a substantial challenge to water availability in rural areas, especially drinking water. Therefore, due to increasing water demands, increases in the population, and economic development, water supply systems are under constant stress. One of the critical uncertainties surrounding the effects of rainfall variability in Africa is the significant impact that it imposes on rural water supply services. The present study analyzes the trends in annual and seasonal rainfall time series in the Wami River Basin to see if there have been any significant changes in the patterns during the period 1983–2017 and how they affect the access to water supply services in rural areas. The study analyzes the trends of rainfall series of three stations using simple regression, Mann–Kendal Test and Sen’s Slope Estimator. The water point mapping datasets were analyzed considering seasonal variation. The analysis showed a statistically significant positive trend in annual rainfall at Kongwa and March–April–May (MAM) seasonal rainfall at Dakawa. The maximum increase in annual rainfall occurred at Kongwa (5.3 mm year−1) and for MAM seasonal data at Dakawa (4.1 mm year−1). Water points were found to be significantly affected by seasonal changes, both in terms of availability and quality of water. There also exists a strong relationship between rural water services and seasons.

Impact of Land-Use/Land-Cover Change on Drinking Water Ecosystem Services in Wami River Basin, Tanzania

“…Population growth and economic development have led to changes in LU/LC worldwide, while ecosystems services are continuously threatened by human activities and stand to be further affected [2,61,62]. Resulting changes can have positive consequences such as increased vulnerability, resulting in a decreased supply of ecosystem services including water availability and quality, especially in arid and semiarid regions [61].…”

“…On the other hand, the other LU/LC categories showed a decreasing trend. Woodland and bushland showed significant decreases, by 697.90 km 2 (4.84%) and 184.92 km 2 (1.21%) respectively. Grassland, forest, and swamp showed a decreasing trend during the study period, by 100 km 2 (0.70%), 32.26 km 2 (0.22%), and 9.01 km 2 (0.06%), respectively.…”

“…In recent years, substantial changes in land-use/land-cover (LU/LC) have taken place due to human activities [1,2]. LU/LC change linked to human factors, such as agricultural loss, overexploitation of forests, and urbanisation, has caused natural resource shortages, including widespread and permanent losses of biodiversity across the sphere [3,4].…”

Rural Water Collection Patterns: Combining Smart Meter Data with User Experiences in Tanzania

“…The DPs are available to all households (discussed below). Across rural Tanzania, the population without basic drinking water service stands at 57% [23], and even communities with recorded water points are not guaranteed year-round service [24].…”

“…The DPs are available to all households (discussed below). Across rural Tanzania, the population without basic drinking water service stands at 57% [23], and even communities with recorded water points are not guaranteed year-round service [24].The PWS investigated in Community A consists of: a 78 m deep borehole with one solar-powered motorised pump (6 m 3 hr −1 capacity with 32 solar panels); 50 m 3 water tank elevated on a hillside; 13 gravity-fed DPs; and pipework. The farthest DP from the tank is 2.6 km.…”