Rainwater Harvesting Technology Research Articles

Rainwater harvesting technologies in arid plains of Argentina: small local strategies vs. large centralized projects

Access to water has been and remains one of humanity’s greatest challenges. Especially in arid plains exposed to significant climatic fluctuations and future global change trends. In the past and present, local communities of the arid plains of central-western Argentina (i.e., Guanacache Lagoons, Cuyo region) have developed multiple strategies to manage water supply problems. The aims of this study are: i) to characterize the different water harvesting technologies (pre-Hispanic and modern) used, and ii) to compare the small local strategies of water harvesting (bottom-up solutions) with the large centralized projects (top-down solutions). On the one hand, we show the transformations of these technologies over time, and the challenges faced by inhabitants in the context of climate change trends. On the other hand, we analyze the role of the state through hydraulic policies and projects implemented by the provincial states over the last two centuries and how this impacted the study area. This review is based on a historical and archaeological bibliography, and recent publications about the region, including articles based on our ethnographic fieldwork. Our results demonstrate the valuable experience accumulated by local populations in water harvesting methods, particularly in areas where groundwater is deep and saline, and shows the adaptability of these technologies in contexts of increasing scarcity. We considered that local indigenous knowledge can largely contribute to the sustainable management of water resources. This study might be useful for decision-makers and water managers in drylands around the world to find and equitable approach that combines technical advances with local knowledge.

Adoption and Impact of Rainwater Harvesting Technology in Nepal

The rainwater harvesting (RWH) technology has been introduced to upland farmers in Nepal who have been practicing rain-fed subsistence agriculture. Using cross-sectional household level data from 282 farmers in four districts of Makwanpur, Palpa, Gulmi and Syangja, probit and treatment-effects models were used to identify factors that influence the adoption of RWH and its impact on farm income. The adoption of rain water harvesting was mostly driven by trainings that farmers received while controlling for age, poverty status and off-farm income. The adoption of RWH technology more than doubles household agricultural and livestock income. Instrumental variable approach was used to check the robustness of the findings. Adopters benefited from an increased supply of irrigation water, which allows them to diversify their crops from cereal production to high-value crops during dry season. Given the many weather-related uncertainties faced by rainfed farmers in Nepal, rain water harvesting is potentially a very useful climate adaptation strategy. These results were robust to alternative model specification and estimation method.

Factors Affecting Rainwater Harvesting Practices: In Case of Assosa Town, Upper Blue Nile Basin, Northwestern Ethiopia

In many parts of the world, conventional water supplies do not exist, are unreliable or prohibitively expensive. Many actual or potential water shortages can be alleviated if the practice of rainwater harvesting becomes widespread. A study was conducted to evaluate the factors affecting rainwater harvesting practices in Assosa city. The reason for starting the research is that the municipality of Assosa suffers from a severe water shortage, especially at the end of the dry season. The study involved 99 randomly selected respondents and purposively selected respondents using a semi-structured questionnaire. Data were collected using a combination of data collection methods including survey interviews, key informant interviews, and direct observation. The data was analyzed using descriptive statistics such as frequency tables to draw conclusions and recommendations. The results showed that lack of funding played a key role in the adoption of rainwater harvesting and, furthermore, lack of information and poor technology contributed to the failure to adopt rainwater harvesting for domestic use. It was determined that roofing materials were not a problem in the area, but storage areas and gutters hindered rainwater collection. We therefore concluded that the implementation of rainwater harvesting systems in Assosa town was hampered by the lack of resources required for the installation of rainwater harvesting systems. In addition, inadequate accesses to information, particularly for women, and lack of knowledge about the maintenance of rainwater harvesting technologies have contributed to the lack of widespread adoption of rainwater harvesting. We recommend making a conscious effort to subsidize rainwater harvesting in this area. The study also recommends strengthening municipal capacities in the area of rainwater harvesting technology, which is expected to be important for improving rainwater harvesting technology.

Optimizing Ridge–Furrow Rainwater-Harvesting Strategies for Potato Cultivation in the Drylands of Northwestern China: A Regional Approach

The arid and semi-arid region of Northwest China plays a significant role in potato production, yet yields are often hampered by drought due to limited precipitation and irrigation water. The ridge–furrow rainwater-harvesting technology is an efficient and widely used technique to relieve drought impact and improve crop yield by changing the micro-topography to harvest rainwater to meet the water demand of crops. An analysis of precipitation, water demand, and runoff data spanning 30 years guided the selection of suitable rainwater-harvesting methods tailored to meteorological conditions. The results showed that potato water demand exceeded precipitation in the region. The mulching approach performed best in the western arid region with the most significant increase in yield and water use efficiency (WUE) and was suitable for the western semi-arid region and the agro-pastoral ecotone. In the potato dryland farming areas, the water deficit increased from southeast to northwest. Specifically, northern Gansu, northern Ningxia, and midwestern Inner Mongolia experienced a water deficit of over 200 mm, and rainwater harvesting combined with irrigation was recommended. Conversely, regarding deficits below 200 mm in southern Gansu, Ningxia, and central Inner Mongolia, a 1:1 or 2:1 pattern of ridges could be applied, and mulching was needed only in the necessary areas. For the southern Qinghai, Shaanxi, and eastern Inner Mongolia regions, ridge–furrow rainwater harvesting could be replaced by flat potato cropping. In summary, rainwater harvesting addresses water deficits, aiding climate adaptation in Northwest China’s arid and semi-arid regions. The implementation of mulching and ridge–furrow technology must be location-specific.

From drops to drums: Assessing rainwater storage’s quality and quantity for addressing water demands in dry periods – A case study from Arusha Tanzania

Sustainable Development Goal 6 highlight the importance of providing reliable, affordable, and safe source of clean drinking water and sanitation for all by 2030. In Tanzania there is a dire need of a water supply strategy due to high levels of natural fluoride contamination in ground water (upto 74 mg/L) and the challenge of meeting water demand during 5 months long dry period. This study assesses social and technical feasibility of implementing rainwater harvesting (RWH) along with treatment technologies that includes Denutritor® to remove ammonia/pesticides and ultrafiltration to eliminate carbon. This integrated technology known as “Mbinguni Maji” is aimed for the long-term water storage to supply drinking water throughout the dry season. The methodology involves i) Assessing the technical feasibility of RWH using database from QGIS and Water Productivity Open-access portal (WaPOR) from the Food and Agricultural Organization of the United Nations; ii) conducting pilot demonstration in 5 different locations in Tanzania; and iii) conducting socio-economic survey for social acceptance of the technology through detailed questionnaires administered to residential homes, medical facilities, schools, hotels, and water kiosk owner. The result indicates that, from technical perspective, there is ample rainfall (average of 1036 mm/year) to supply water throughout the dry season, primarily for drinking and cooking purpose only (upto a maximum of 10 lpcd). The pilot demonstration confirms that the Mbinguni Maji RWH technology produce water that meets WHO water quality standards. The produced water is free from nutrients like carbon and ammonia, ensuring the possibility of long-term storage without bacterial and algal growth. Furthermore, Lab scale demonstration of Denutritor® show promising result of removing nitrite, ammonia even at high elevated temperature (30 °C), which can be effectively applied in Tanzania. In terms of social acceptance, RWH technology is already widely practised in Tanzania during the rainy season. However, the initial investment costs and operation & maintenance (O&M) concerns hinder the usage of RWH technology. Therefore, to ensure the long-term sustainability of RWH technologies, there is a need of development of comprehensive business plan and community awareness campaign.

Adoption of Rainwater Harvesting Technology and Drip Irrigation Automation by Akur Muda Farmer Group, Ngaglik District, Sleman Regency, Yogyakarta

Adoption of Rainwater Harvesting Technology and Drip Irrigation Automation by Akur Muda Farmer Group, Ngaglik District, Sleman Regency, Yogyakarta

Adaptation to climate change: state of art technologies

PurposeThe world is increasingly threatened by climate change. As the dimensions of this danger grow, it becomes essential to develop the most effective policies to mitigate its impacts and adapt to these new conditions. Technology is one of the most crucial components of this process, and this study focuses on examining climate change adaptation technologies. The aim of the study is to investigate the entire spectrum of technology actors and to concentrate on the technology citation network established from the past to the present, aiming to identify the core actors within this structure and provide a more comprehensive outlook.Design/methodology/approachThe study explores patent citation relationships using social network analysis. It utilizes patent data published between 2000 and 2023 and registered by the US Patent and Trademark Office.FindingsStudy findings reveal that technologies related to greenhouse technologies in agriculture, technologies for combatting vector-borne diseases in the health sector, rainwater harvesting technologies for water management, and urban green infrastructure technologies for infrastructure systems emerge as the most suitable technologies for adaptation. For instance, greenhouse technologies hold significant potential for sustainable agricultural production and coping with the adverse effects of climate change. Additionally, ICTs establish intensive connections with nearly all other technologies, thus supporting our efforts in climate change adaptation. These technologies facilitate data collection, analysis, and management, contributing to a better understanding of the impacts of climate change.Originality/valueExisting patent analysis methods often fall short in detailing the unique contributions of each technology within a technological network. This study addresses this deficiency by comprehensively examining and evaluating each technology within the network, thereby enabling us to better understand how these technologies interact with each other and contribute to the overall technological landscape.

A holistic multi-tiered decision framework for evaluating rainwater harvesting potential in arid regions: A case study of the southeastern basin of Djibouti

Rainwater harvesting (RWH) stands as a strategy to mitigate the widespread challenge of water scarcity in arid and semi-arid regions worldwide. The practice of capturing and storing stormwater via different RWH technologies during wet periods can serve as a means of replenishing stressed local aquifers. However, identifying optimal locations conducive to the successful implementation of RWH initiatives accounts for a multi-tiered and intricate challenge. Furthermore, contemporary methodologies utilized to assess the potential of RWH often adhere to conventional paradigms, exhibiting a dearth of sophisticated mathematical foundations. Hence, this study proposes a hybrid approach that integrates the fuzzy analytic hierarchy process (AHP) and the VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) algorithms to delineate suitable RWH sites. The proposed framework was subsequently applied in the southeastern basin of Djibouti, a nation facing acute water stress. The assessment of RWH potential in this research is predicated upon twelve decision criteria, organized into three principal dimensions: physical, environmental, and socio-economic aspects. The results highlighted the vitality of environmental (47.67%) and physical (37.98%) dimensions, whereas the socio-economic (14.35%) cluster was deemed less significant according to the established decision framework. Furthermore, the resultant suitability map portrays that a substantial area of the basin, approximately 872.5 km2 (equivalent to 64.25%), exhibits moderate to very high suitability for the implementation of diverse RWH structures, including check dams, percolation tanks, and infiltration ponds. The reliability of the analysis is verified through sensitivity analysis, underscoring the robustness of the decision model. This contributes to the empowerment of decision-makers and the research community, facilitating the creation of accurate RWH potential maps, and thereby advancing effective water resource management strategies for water stressed regions.

Strengthening Community Capacity To Face Drought With Rainwater Harvesting Technology

Kalanganyar Village is a village located at the easternmost tip of Sidoarjo Regency, East Java. This village makes a major contribution to the field of aquaculture and processing. However, in the rainy season, this village experiences inundations and even floods in some areas, and during the dry season experiences drought or difficulty getting clean water. Based on this, this Community Service activity aims to help provide solutions by applying Rainwater Harvesting technology. The method used in this activity begins with permits in related agencies, then planning, counseling, practice making rainwater harvesting installations, and evaluations are carried out. With this activity, the Kalanganyar Village Community can make RHT installations independently after this activity, there are no inundations and floods in the rainy season, in the dry season clean water needs are still met, and the Kalanganyar Village community has been able to increase their capacity in dealing with drought to prevent non-natural disasters

Assessment of rainwater harvesting potential based on field observations in Jagakarsa District area, South Jakarta

Jagakarsa is one of the districts in South Jakarta that has a rainwater catchment area. Problems arise as a result of the high rate of population growth, which has an impact on changes in land use and increased surface runoff, causing flooding. On the other hand, the absence of clean water provision facilities from the government means that people use groundwater-drilled wells to meet their daily clean water needs. Sustainable groundwater consumption has an impact on land subsidence and vulnerability to groundwater availability. Therefore, it is necessary to carry out research. This research seeks to assess the potential for rainwater harvesting based on field observations. The research was carried out by analyzing rainfall data, field surveys, research program socialization, and community socio-economic analysis. Rainfall is high, with an annual average of 2809.7 m. 98% of respondents use drilled groundwater wells with a wells depth in the deep aquifer layer, and public interest in rainwater harvesting (RWH) technology is high. These show the potential for implementing RWH in the study location. This research is an initial study; for the integrated implementation of RWH, further research is needed after this study.

Evaluation of water productivity of smallholder irrigation along a Sand River, in the Maigobo watershed of northern Ethiopia

Sand dams are a type of rainwater harvesting technology that can increase groundwater recharge in dry land environments. They are constructed across seasonal sandy rivers and trap sand and water during floods. The sand acts as a natural filter and storage medium for the water, which can be extracted by the local communities through wells, pumps, or scoop holes. This research aims to evaluate agricultural water productivity based on water consumption (ETa) and biomass production of smallholder irrigation schemes along a sand river with a sand dam in the riverbeds of northern Ethiopia. Remotely sensed satellite data, WaPOR (Water Productivity through Open access of Remotely sensed derived data) database was used to estimate water productivity in the arid and semi-arid area. Following the installation of the sand dam at the irrigated parts of the Mai Gobo watershed, both the annual and seasonal values increased over a number of years, according to the spatial analysis of ETa and biomass production. For instance, the maximum seasonal ETa before the dam was about 70 mm/season, whereas after the dam the spatially analysed ETa reached 174 mm/season. Likewise, maximum seasonal biomass production of 1117 kg/ha and 4433 kg/ha were obtained before and after the construction of the sand dam, respectively. Agricultural water productivity at the irrigated plots of the Mai Gobo watershed was also improved from 1.4 kg/m3 to 2.9 kg/m3 before and after the sand dam respectively. Generally, the output of the study can be used as an input for the concerned stakeholder to take measures against the water scarcity problem in the study area. The study also contributes to the scientific knowledge and understanding of the hydrological and agronomical impacts of the sand dam in the arid and semi-arid regions.

Determinants of the Adoption of Charco Dam Rainwater Harvesting Technology by Pastoralists in Semi-Arid Areas of Monduli District in Tanzania

The use of water harvesting ponds in Tanzania known as charco dams in watering livestock have been developed to enhance livestock production in semi-arid areas. However, the adoption of charco dam has been very low. This paper examined the determinants of the adoption of charco dam by pastoralists in semi-arid areas of Monduli District in Tanzania. The study used a cross-sectional research design where data were collected at a single point in time. Quantitative data were collected by using pre-tested structured questionnaire from 367 respondents who were randomly selected from seven villages, namely Moita Kipok, Moita Kilorit, Kilimatinde, Moita Bwawani, Makuyuni, Mbuyuni and Naiti in Monduli District. The collected data was entered into SPSS.20 for analysis. Data was analysed using frequency, percentages, and a binary logistic regression model. The study results show that the intervening factors (perceived advantages and disadvantages of charco dam) have a slightly high influence on the adoption of charco dam with predictive power R2 ranging from 29.5 to 44.5 per cent as compared to independent variables with predictive power R2 ranging from 27 to 37 per cent at a 5 per cent level of significance. Furthermore, the study results indicate that the independent variables namely socio-economic factors specifically age (p=0.000), household size (p=0.002), off-farm income (p=0.025), livestock keeping experience (0.001), herd size (0.002) and institutional factors including access to extension services (p=0.030) and subsidies (p=0.005) have an influence on the adoption of charco dam. This study recommends policymakers to devote more weight to perceived advantages and disadvantages of charco dam technology while constructing charco dam rainwater harvesting projects in order to influence pastoralists to accept the technology and increase water access for livestock in semi-arid areas.

New technology adoption in rural areas of emerging economies: The case of rainwater harvesting systems in India

Technological advancements can accelerate the attainment of Sustainable Development Goals (SDGs). However, technology adoption is associated with complex, interrelated factors, even more so in the context of rural areas in emerging economies. We examine the adoption of one technology that can be crucial for resolving water scarcity issues facing countries around the world–the Rainwater Harvesting (RWH) technology and the critical success factors (CSFs) that promote its adoption in rural India. Building on an extensive literature review, focus group discussions, and field visits, this paper identifies a list of factors that promote its adoption. To derive the CSFs, the relevance of each factor is analysed using Fuzzy-Delphi, and the significance is determined using D-DEMATEL technique. The novel results presented here suggest that awareness about RWH technologies, their perceived usefulness, ease of use, and tax incentives for companies are some crucial factors that can increase RWH technology adoption. Furthermore, community-based workshops explaining the architecture and operational aspects of the RWH System as well as simplifying the RWH system architecture can accelerate its usage in rural areas. Based on these results, the paper presents a new roadmap for leveraging technology to attain SDGs in rural areas of developing countries.

Impact of Climate Change on water security and Endorsing importance of Rainwater Harvesting Technology in Nepal

The day-by-day increment in the concentration of greenhouse gases (GHGs) in the atmosphere is widely believed to be a main contributing factor for climate change. It affects widely on diverse sectors such as water resources, agriculture, forestry, human health, biodiversity, and snow cover and aquatic life. Nepal is experiencing the adverse impact of climate change; this includes such as a variability in temperature and precipitation, overbank flooding from snow-fed rivers, and variability in available river and stream water quantity. Climate in the Nepal Himalayas is changing faster than the global average. Moreover, the changes in the high-altitudes have been found more pronounced than in the low-altitudes. Since, there is no definite trend that could be found in the annual precipitation records, clear decreasing trends could be seen in annual number of rainy days during the study period of 1971-2000. The glaciers in the Nepal Himalayas are shrinking rapidly and there will be no glaciers left by 2180. An accelerated glacier melt will cause an increase in water availability at the beginning but ultimately a decrease in water availability after the glaciers disappear. This will widen the gap between water supply and demand. Changing climate may further exacerbate the water stress which already happening in Nepal due to the monsoon dominated climate. Climate change (CC) will also further increase the seasonal imbalance- too much of water during rainy season and too less of it during dry seasons. Rainwater harvesting technology has the potential to provide numerous benefits to communities and individuals, particularly in areas where water resources are scarce or unreliable. From the analysis and through our research work it is found that if we can simply install and construct rainwater harvesting technology in our individual household only. It nearly fulfills about 15-25% of our domestic water demand. As in urban and rural area of Nepal still nearly about 50% of water demand is fulfilled by groundwater source which increase to 60-70% in dry season. The projected physical impacts of climate change on water resources would have substantial socioeconomic impacts and consequences for Nepal. The hydropower potential and agricultural production would be seriously affected by global warming. A reduction in agricultural production would be experienced due to water security and have significant impact on the food security and livelihoods of the subsistence farmers, who make the majority of the Nepal’s population. As the urgent need for climate change mitigation remains crucial, putting all the necessary resources and institutions in place for future adaptation is indispensable. The Inter-governmental Panel on Climate Change (IPCC) has listed rainwater-harvesting as a key strategy for a planned adaptation in the water sector. The policy statements about rainwater harvesting-based climate change adaptation are currently not being effectively coordinated.

Integration and implementation of rainwater harvesting technologies in development programs, planning and budgeting in Matungulu Sub-County, Machakos County, Kenya

The constitution of Kenya 2010 placed the supply of water and services related to sanitation as a devolved function of County Governments. The clear delineation of roles between the County and National Governments have not significantly improved access to potable and clean water to households. Thirty-six percent of Kenya’s population in Arid and Semi-Arid Lands (ASAL) still have to walk many kilometers in search for water for animal and human utilization There has been introduction of new rainwater harvesting technologies (RHT) that can alleviate the water scarcity, however little progress has been made on improvement of access to clean water in ASAL areas. There is, therefore, need to investigate the initiatives by the County Government of Machakos to integrate and implement water harvesting technologies in its development programs, planning and budgeting among households. Structured questionnaires were utilized to fetch primary data on integration and implementation of rainwater harvesting technologies which were then analyzed. Data was presented using tables, Charts and bar graphs to provide clarity of the findings. Calculation of arithmetic mean, standard deviation, Analysis of variance and regression analysis was done in order to deduce clear understanding of the findings. Documentary evidence was used to establish the programs and initiatives put in place by the County Government. The findings suggested that the County Government had put in place mechanisms to integrate RHTs in its development agenda however, the cost remained the biggest impediment to integration. A regression analysis showed that the Integration of RHT had a positive and significant effect on household livelihoods (β= 0.755, t=22.351, p=0.000<0.05). The study recommends that the County Government of Machakos develop programs to support integration of RHTs including providing subsidies, training, engaging development partners to finance rainwater harvesting and providing technical support.

Identifying potential sites for rainwater harvesting ponds (embung) in Indonesia's semi-arid region using GIS-based MCA techniques and satellite rainfall data.

People have used rainwater harvesting (RWH) technology for generations to a considerable extent in semi-arid and arid regions. In addition to meeting domestic needs, this technology can be utilized for agricultural purposes as well as soil and water conservation measures. Modeling the identification of the appropriate pond's location therefore becomes crucial. This study employs a Geo Information System (GIS) based multi-criteria analysis (MCA) approach and satellite rainfall data, Global Satellite Mapping of Precipitation (GSMaP) to determine the suitable locations for the ponds in a semi-arid area of Indonesia, Liliba watershed, Timor. The criteria for determining the location of the reservoir refer to the FAO and Indonesia's small ponds guideline. The watershed's biophysical characteristics and the socioeconomic situation were taken into consideration when selecting the site. According our statistical analysis, the correlation coefficient results of satellite daily precipitation were weak and moderate, but the results were strong and extremely strong for longer time scales (monthly). Our analysis shows that about 13% of the entire stream system is not suitable for ponds, whereas areas that are both good suitability and excellent suitability for ponds make up 24% and 3% of the total stream system. 61% of the locations are partially suited. The results are then verified against simple field observations. Our analysis suggests that there are 13 locations suitable for pond construction. The combination of geospatial data, GIS, a multi-criteria analysis, and a field survey proved effective for the RWH site selection in a semi-arid region with limited data, especially on the first and second order streams.

Study of Contact Time and Media Thickness on Rainwater Harvesting Technology Filtration at Tidar University

Rainwater harvesting as an alternative raw water source can reduce water runoff. However, rainwater has been in contact with various pollutants in the air. In testing in Building 3, Faculty of Engineering, Tidar University, rainwater contained levels of E. Coli 8 CFU/100ml and Coliform 69 CFU/100ml which exceeded the quality standard of the Minister of Health Regulation No. 32 of 2017. This study aims to see the effect of media thickness and contact time on each mediA to improve rainwater quality using the Vertical Flow Roughing method. Up Flow filter flow with 3 filters containing zeolite gravel, activated carbon, and volcanic sand, with each having 3 different thickness variations, namely 60 cm, 70 cm, and 80 cm. The filter is operated for 18 minutes with sampling every 6 minutes. The results of logistic regression and log likelihood test showed that there was no significant effect on all filtration media in reducing the value of E. Coli and Coliform, but the highest efficiency occurred at 18 minutes with a thickness of 80 cm in each medium. In zeolite gravel filtration, the efficiency of reducing E. Coli and Coliform reaches 100%. In activated carbon filtration, the efficiency of E. Coli reduction was 100% and Coliform 51%. In volcanic sand filtration, the efficiency of E. Coli reduction is 100% and Coliform is 35%.

MODELING OF GROUNDWATER LEVEL CHANGES DUE TO DEEP WELL EXTRACTION USING MODFLOW IN THE NORTH OF BANDAR LAMPUNG

The growth rate of urban areas in the north of Bandar Lampung has caused the extraction of groundwater resources through deep well pumping to increase. Therefore, it is necessary to study the impact of pumping to prevent groundwater depletion. This study performs numerical simulation modeling to identify the impact of deep well pumping on changes in groundwater levels in three sub-districts north of Bandar Lampung city. Modeling is done using MODFLOW-6 and ModelMuse as a graphical user interface (GUI). The simulation method uses steady-state and transient models with four stress periods in 2000, 2010, 2020, and 2030. A total of 30 data wells are used for model setup, and 15 of them as observation and validation points. The simulation results show that hydraulic head changes occur at depths of 10 m to more than 40 m. Drawdown and groundwater head changes are concentrated at deep well points with a radius of up to 1 km. The model also successfully identified a decrease in groundwater level to more than 8 m in the deepest well area DW1. Thus, it is necessary to take action that can overcome the impact of changes in groundwater level due to pumping from deep wells. Furthermore, groundwater storage engineering can be one solution by utilizing rainwater harvesting technology to recharge the groundwater aquifer system.

Rain Water Harvesting Technology: Drinking water fulfillment and water conservation nearby landfill area

The drawback of groundwater quality occurs due to minimum treatment of waste management in the landfill. The research objectives are to know the groundwater quality around the landfill study site, rainwater potential for drinking water purposes, and decreasing runoff due to rainwater harvesting technology implementation. The well water samples were collected from eight wells surrounding the landfill. Rainwater samples were collected from rainwater harvesting technology installation. Water quality parameters consist of total coliform, pH, and Total Dissolved Solids (TDS). Water conservation was observed by infiltration and precipitation. Total coliforms of well water are higher than rainwater. Furthermore, based on acidity and TDS values, well water is higher (pH 6.5-8.5 and TDS 188.8 + 128.7 ppm, respectively) than rainwater (pH 6.1 + 0.2 and TDS 8.4 + 1.4 ppm, respectively). Based on three parameters, rainwater is more proper for drinking water than well water in the study site. Rainwater harvesting technology is able to reduce runoff by 58.42% with the rainwater catchment area around 7,095 m2. Waste management in landfills should concern with groundwater pollution. Rainwater harvesting technology is a potential solution for drinking water supply in water crisis areas.

Factoring labour when comparing in situ rainwater harvesting technologies for semi-arid areas of central Tanzania

ABSTRACT Erratic rainfall, high evapotranspiration rates and droughts are major factors limiting crop production in semi-arid areas. Tied ridges that have crossed ties within the furrow are among the physical soil and water conservation measures. During the 2018/19 and 2019/20 seasons, we examined the efficacy of repaired tied ridges for maize crop (Zea mays) and sorghum (Sorghum bicolor) in Kongwa district of Tanzania as an alternate labour saving strategy for managing climate risks associated with variable rainfall. Treatments consisted of three tillage methods: conventional tillage (CT) which involved the preparation of a flat seedbed using handhoe, annually constructed tied ridges (ATR) and tied ridges that had been constructed during the previous season and had been repaired (residual tied ridges–RTR). Data were collected on labour requirements and crop performance. RTR increased economic returns by 29% and 80% over ATR and CT, respectively. Maize grain yield shows a trend of RTR >ATR>CT with values ranging from 2465 kg ha−1 to 4185 kg ha−1 (P < 0.01). While tillage and/or variety did not influence sorghum grain yield significantly (P > 0.05). The use of RTR is recommended because of low labour requirements and greater economic benefits than CT and ATR under maize cropping systems.