Rainwater Storage Research Articles

Study of farmer perception about the impact of climate variability and change on dairy farming for adaptation strategy

This study aims to examine the perception of farmers on climate variability and change and what aspects were most affected by climate variability and change as well as what adaptation strategies can be carried out by farmers. This study was conducted in July – September 2021 at the dairy farm of a livestock farmer group in the city of Salatiga, Central Java Province, Indonesia. A total of 286 farmers from a total of 11 groups were used as respondents in this study. Each group had 26 ± 10.94 dairy cows. Data were obtained through interviews and filling out questionnaires. Descriptive statistical analysis and Friedman’s test (K-related sample test) with SPSS version 25 were used to analyze the data. The percentage of farmers who believe in the phenomenon of climate change was higher than those who do not. In general, farmers know about climate change through personal observations. Most farmers feel that the temperature continues to increase every year, but during the rainy and dry seasons, there was no change. Based on the farmer’s perception, the biggest impacts caused by climatic conditions were the availability of forage and water and milk production. Adaptation strategies that can be carried out by farmers to overcome the availability of feed were making silage, using agricultural waste and the role of the government was needed to provide concentrated subsidies. Drilling wells and rainwater storage can be used as a strategy to overcome restrictions on water availability.

Deposition and Microbial Analyses from Roof-Top Sediments Within Different Sanitation Environments

Since the building roof acts as hub for atmospheric sediment deposition, the attached microbes can enter rainwater storage tank with ease to cause health issue for rainwater users. This study aims to explore the trend of roof-top deposited microbes in the different areas of Ikorodu local Government Area at Lagos, Nigeria. This paper also tests the hypothesis that the roof sediment deposition being a significant source to home bacteria. The total deposition rate on the roof for 34 weeks, which include 17 rainy and 17 dry weeks, were investigated. The enumerated bacteria was obtained from the roof deposit samples, where four representative different sites have been analysed to study the solid depositions and microbes within the area thoroughly. The sites were selected judging by their levels of sanitation and vegetation rate. The experimental investigations showed that enumerated microbes and total suspended solid (TSS) depositions in the different areas were higher in the dry season compared to rainy season, and the highest deposition was experienced in the Harmattan period. In addition, the results showed that areas with poor drainage infrastructure and poor sanitation have the roof-top deposition with higher bacterial count than good sanitation areas; while the unpaved and unvegetated areas produced higher deposits than the paved and vegetated areas. In terms of contamination sources, this study has illustrated that the particulate deposition on the roof-top prior to collection has further contaminated the roof-harvested rainwater.

Pepe Boyolali River: Analysis of Water Quality Using the Pollution Index Method

This study uses the pollutant index method to determine the form of river utilization by the surrounding community and the level of river water pollution. The research method used in this study is qualitative and quantitative analysis. Qualitative descriptive analysis method is used to analyze the form of river utilization by the community. Analysis of river water quality used quantitative method which refers to the Decree of the Minister of Environment 115/2003 concerning Determination of Water Quality Status using the Pollution Index (PI) method. The results of the analysis show that the community uses the Pepe River as a source of water and rainwater storage, waste disposal sites, fishing grounds, drainage channels, and agricultural irrigation. So that it has the potential to experience water pollution due to the entry of domestic-industrial waste. Based on PI, the flow of the Pepe River is proven to be lightly polluted, with the results of several parameter measurements showing results above the quality standard. Therefore, one of the recommendations that can be applied to overcome these problems is to develop the concept of Community-Based Development by involving the active role of all society levels in planning and implementing river management and development activities.

Analisis Efektivitas Daya Tampung Embung Taman Firdaus Universitas Sriwijaya

Floods occur due to reduced water catchment areas due to increased land use, both for settlements and economic activities. The purpose of this research is to analyze the storage capacity of the embankment. The Firdaus Taman Firdaus Reservoir of Sriwijaya University (UNSRI) is located in the Ogan Ilir district and is useful as a place for rainwater storage and flood control. Embung has many benefits to meet the water needs of UNSRI. The UNSRI reservoir has an area of ​​24 hectares, the west reservoir is 8 m from the bottom and 50 m long. Results of data analysis, the volume of the reservoir with a depth of 5 m with an area of ​​pond 1 covering an area of ​​423804.79 m2 can accommodate water with a storage volume capacity of 2119023.95 m3. The results of testing the average water content in the original soil (w) = 87.38 %. The test results for the average soil specific gravity (Gs) are 2.19. The results of the Atterberg limit test, the liquid limit value in soil (LL) = 57.00 %, the plastic limit in soil (PL) = 48.37 %, and the plasticity index in soil (IP) = 8.63 %. Based on the AASTHO classification, the soil in the UNSRI Firdaus Taman Embung belongs to group A-2-5, as silt or loamy gravel and sand. Meanwhile, based on the USCS classification, it is classified as Silts and Clays (CH). The results of the permeability test are the permeability value (K) = 3.034191 x 10-5 cm/s, which is low permeability.

Evolution at the arid extreme: the influence of climate on sand termite colonies and fairy circles of the Namib Desert.

In the hyperarid Namib Desert, the sand termite Psammotermes allocerus Silvestri, 1908 (Isoptera: Rhinotermitidae) establishes colonies that create conspicuous, barren patches known as 'fairy circles' on permeable, sandy soils. The central bare areas of fairy circles serve the key function of storing moisture received from sparse rainfall. The sandy soil texture allows rapid infiltration and percolation of precipitation, while localized herbivory by the termites creates the bare patch, thereby reducing the rapid loss of soil moisture by the uptake and transpiration of water by plants. The resulting storage of rain water even during prolonged periods of drought enables perennial life in hyperarid desert environments and forms a globally unique example of ecosystem engineering by social insects. During the past decade, most publications primarily debated the origin of fairy circles. Here, we contribute to the special issue with a focus on the functional and evolutionary dimension of the structure of the Psammotermes colony with two differing nest types and two spatially separated key resources, as a successful adaptation to extreme desert environment. The paper is primarily a review and a synthesis of previous work, with the inclusion of new, relevant findings. This article is part of the theme issue 'The evolutionary ecology of nests: a cross-taxon approach'.

A Theoretical Nonlinear Regression Model of Rainfall Surface Flow Accumulation and Basin Features in Park-Scale Urban Green Spaces Based on LiDAR Data

Green infrastructure is imperative for efficiently mitigating flood disasters in urban areas. However, inadequate green space planning under rapid urbanization is a critical issue faced by most Chinese cities. Aimed at theoretically understanding the rainwater storage capacity and improvement potential of urban green spaces, a synthetic simulation model was developed to quantify rainfall surface flow accumulation (FA) based on the morphological factors of a flow basin: the area, circumference, maximum basin length, and stream length sum. This model consisted of applying the Urban Forest Effects-Hydrology model (UFORE-Hydro) to simulate the actual precipitation-to-surface runoff ratio through a procedure involving canopy interception, soil infiltration, and evaporation; additionally, a relatively accurate multiple flow direction-maximum downslope (MFD-md) algorithm was applied to distribute the surface flow in a highly realistic manner, and a self-built “extraction algorithm” extracted the surface runoff corresponding to each studied basin alongside four fundamental morphological parameters. The various nonlinear regression functions were assessed from both univariable and multivariable perspectives. We determined that the Gompertz function was optimal for predicting the theoretical quantification of surface FA according to the morphological features of any given basin. This article provides parametric vertical design guidance for improving the rainwater storage capacities of urban green spaces.

IoT Enable Intelligent Smart Bin for Garbage Monitoring based on Real-Time Data Analysis

Abstract: The amount of waste being disposed of has become an issue due to the world's population growth and rapid urbanization because the infrastructure is not sufficiently established. Malaria, dengue fever, and cholera are just a few of the illnesses that render human life penalized by erroneous monitoring and cleaning of a city's trash bins. Humans suffer as a result in a variety of ways, thus in order to prevent the worst case scenario, waste bins must be monitored remotely so that they may be cleaned on a regular basis, allowing urban residents to live more safely and comfortably. By examining a bin's various components, including its level of trash, indoor humidity, temperature, and any harmful gases that might be produced due to erroneous monitoring, the burning of waste, or the storage of rainwater in a bin, the proposed work determines the interior condition of a waste bin. Here, the idea of IoT is applied to ongoing remote monitoring to ensure that the bins don't overflow, don't emit any dangerous gases or smoke, and don't pollute the environment around people.

Low-regret climate change adaptation in coastal megacities – evaluating large-scale flood protection and small-scale rainwater detention measures for Ho Chi Minh City, Vietnam

Abstract. Urban flooding is a major challenge for many megacities in low-elevation coastal zones (LECZs), especially in Southeast Asia. In these regions, the effects of environmental stressors overlap with rapid urbanization, which significantly aggravates the hazard potential. Ho Chi Minh City (HCMC) in southern Vietnam is a prime example of this set of problems and therefore a suitable case study to apply the concept of low-regret disaster risk adaptation as defined by the Intergovernmental Panel on Climate Change (IPCC). In order to explore and evaluate potential options of hazard mitigation, a hydro-numerical model was employed to scrutinize the effectiveness of two adaptation strategies: (1) a classic flood protection scheme including a large-scale ring dike as currently constructed in HCMC and (2) the widespread installation of small-scale rainwater detention as envisioned in the framework of the Chinese Sponge City Program (SCP). A third adaptation scenario (3) assesses the combination of both approaches (1) and (2). From a hydrological point of view, the reduction in various flood intensity proxies that were computed within this study suggests that large-scale flood protection is comparable but slightly more effective than small-scale rainwater storage: for instance, the two adaptation options could reduce the normalized flood severity index (INFS), which is a measure combining flood depth and duration, by 17.9 % and 17.7 %, respectively. The number of flood-prone manufacturing firms that would be protected after adaptation, in turn, is nearly 2 times higher for the ring dike than for the Sponge City approach. However, the numerical results also reveal that both response options can be implemented in parallel, not only without reducing their individual effectiveness but also complementarily with considerable added value. Additionally, from a governance perspective, decentralized rainwater storage conforms ideally to the low-regret paradigm: while the existing large-scale ring dike depends on a binary commitment (to build or not to build), decentralized small- and micro-scale solutions can be implemented gradually (for example through targeted subsidies) and add technical redundancy to the overall system. In the end, both strategies are highly complementary in their spatial and temporal reduction in flood intensity. Local decision-makers may hence specifically seek combined strategies, adding to singular approaches, and design multi-faceted adaptation pathways in order to successfully prepare for a deeply uncertain future.

Modeling Rainwater Harvesting and Storage Dynamics of Rural Impoundments in Dry Chaco Rangelands

Transporting water to supply livestock is one of the great challenges of the drylands. Ranchers usually make impoundments, filled by runoff, to access freshwater for cattle supply in flat rangelands. The aim of this study was to understand rainfall-runoff generation and water storage temporal dynamics of impoundments in the Dry Chaco rangelands (Argentina). Thus, we instrumented six impoundments over three consecutive years and analyzed water storage data by developing a probabilistic model. For all impoundments, the rainfall event size thresholds to generate runoff presented values between 15 and 33 mm. Once they reached this threshold, the water gain response slopes presented values between 19 and 99 m3 mm−1. Loss patterns of water storage were described by exponential or linear functions. The predicted water storage dynamics presented high accuracy with the observed time series for all impoundments (RMSD between 380 and 1320 m3). The model only needs daily rainfall and air temperature to be run, making it easy to be used by scientists, ranchers, or local decision makers. It may be used to explore the hydrological functioning of small and seasonal water bodies of different sites of the world exposed to drought episodes caused by high climate variability and/or climate change.

Drought decreases water storage capacity of two arboreal epiphytes with differing ecohydrological traits

Arboreal epiphytes, plants that grow on trees, can significantly increase rainwater storage and evaporation (i.e., “interception”) within canopies. Drought conditions may affect this hydrological role, as epiphytes' physiological responses change leaf properties that affect water retention. Drought-induced changes in epiphyte water storage capacity could substantially alter canopy hydrology, but have not been studied. We tested the effects of drought on the water storage capacity (Smax) of leaves and leaf properties of two epiphytes with distinct ecohydrological traits: resurrection fern (Pleopeltis polypodioides), and Spanish moss (Tillandsia usneoides). Both species are common in maritime forests of the Southeastern USA, where climate change is expected to decrease precipitation in spring and summer. To simulate drought, we dried leaves to 75 %, 50 %, and ~25 % of fresh weight, and quantified their Smax in fog chambers. We measured relevant leaf properties: hydrophobicity, minimum leaf conductance (gmin; a measure of water loss under drought), and Normalized Difference Vegetative Index (NDVI). We found that drought significantly reduced Smax and increased leaf hydrophobicity for both species, indicating that lower Smax may be due to shedding of droplets. While the overall reduction in Smax did not differ between the two species, they exhibited distinct drought responses. Dehydrated T. usneoides leaves had lower gmin, demonstrating the ability to limit water loss under drought. P. polypodioides increased gmin when dehydrated, consistent with its extraordinary ability to withstand water loss. NDVI decreased with dehydration in T. usneoides but not P. polypodioides. Our results suggest that increased drought may have a dramatic effect on canopy water cycling by reducing the Smax of epiphytes. Reduced rainfall interception and storage in forest canopies could have widespread effects on hydrological cycling, thus understanding the potential feedbacks of plant drought response on hydrology is crucial. This study highlights the importance of connecting foliar-scale plant response with broader hydrological processes.

High Incidence of Contact Dermatitis in Communal Rainwater Harvesting Users in a Rural Area of Sampang, Madura, East Java, Indonesia

Marparan village in Sampang, Indonesia uses a communal rainwater harvesting system (RWHS) for collecting water during the dry season. This study aimed to assess the quality of the water in the communal rainwater catchment pond (CRHP) and investigate the occurrence of contact dermatitis among the community members. The research followed an observational approach with a cross-sectional design, involving 50 individuals randomly selected from the user community of the CRHP for sanitation hygiene purposes. Water samples were collected from the CRHP and analyzed for physical characteristics, pH level, and surfactant content. The results revealed that the water in the communal rainwater storage pond did not meet the quality standards established by the Ministry of Health Indonesia. Additionally, a significant association was found between age and the occurrence of contact dermatitis. However, no significant relationships were observed between variables such as activity type, exposure frequency, and the incidence of contact dermatitis. Moreover, no relationships were identified between activity type, exposure frequency, duration of exposure, and the occurrence of contact dermatitis. It was observed that respondents did not rinse with clean water after using the communal rainwater storage pond for bathing or washing clothes. Therefore, it is recommended that individuals rinse with clean water after engaging in activities involving the use of the rainwater storage pond to minimize the risk of contact dermatitis.

A Case Study of Leaf Wettability Variability and the Relations with Leaf Traits and Surface Water Storage for Urban Landscape Plants

Leaf wettability, the affinity of a leaf surface to water droplets, affects the interactions between leaves and external environments. This study aimed to determine the interspecific and seasonal variabilities of leaf wettability across 30 common landscape plants, and their relationships with leaf functional traits, surface micromorphology and rainfall interception in Hefei city, China. Results indicated that leaf wettability was species-specific, and the adaxial and abaxial contact angles ranged from 63° to 134° and 66° to 134°, respectively, with the adaxial surface proving more wettable. Leaf wettability gradually increased from spring to winter. Classification of life forms revealed that there were no significant wettability differences among trees, shrubs and herbs, and between evergreen and deciduous plants, but deciduous plants’ wettability increased more significantly in winter. Leaf wettability was not significantly correlated with any leaf functional traits. Single surface microscopic parameters also had low correlations with leaf wettability. Instead, the low-wettability species were found to possess more prominent epidermis cells, dense waxy layers or trichomes on leaf surfaces. Leaf wettability was the best predictor of surface rainwater storage within all functional traits. Our results highlighted that leaf wettability was variable between different species and growth periods due to micromorphological differences, and significantly affected rainfall interception at the leaf scale, which may have great significance for evaluating plant hydrological function in urban areas.

Forensic assessment of landslides induced by environmental changes in Sumedang, Indonesia, an important step for the future disaster prevention

Landslide forensics assessment was conducted in Cimanggung, Sumedang with the aim of identifying the causes and processes of landslides to guide the critical step of future disaster prevention. The methodology includes investigations on geology, lithology, hydrology, land cover, land-use changes, and rainfall triggering the landslide. Unmanned Aerial Vehicles were used to investigate detailed spatial geomorphology for determining landslide development. The forensic assessment of the landslide that occurred in Cimanggung, Sumedang, on January 9, 2021, revealed the role of environmental changes. The conversion of open land to residential areas affects the water balance. The surface burden to the site on the hilltop by houses and toe-side cutting at the bottom of the slope has occurred. Changes in land conditions and hydrology, along with lithology thickness and variations, are essential aspects of the landslide incident. During the high rainfall rate, there is more water runoff, and the flow could be concentrated in a paleo channel formed by thicker unconsolidated sediments. The combination of these aspects destabilized the slope causing it to slide. Water management, particularly drainage improvement, should be established to prevent excessive runoff and centralized infiltration. Detailed hazard zonation, site delineation, and rainwater storage could be developed to avoid future landslides.

Impact of Climate Change on Agricultural Sector of a Drought Prone Area: A Case of Bargarh District, Odisha

Abstract: Global climate change is a process that affects every one of us differently. Significant climate changes have been seen throughout the past century. The life of more than 700 million people in rural India depends on climate-sensitive businesses like agriculture, forestry, and fisheries as well as on natural resources like water, feed, and biodiversity. Today's climate variabilityrelated uncertainties pose serious threats to global economic growth. This paper aims to analyse how climate change causes drought in an area and how drought has its impact on agricultural sector and production. Drought is caused due to deficiency of rainfall and it is a complex natural hazard. Unlike other environmental disasters, it starts slowly, has its effect for a longer duration of time and covers a vast area. In India, it upsets the country’s food security by seriously affecting our agricultural economy, which is heavily dependent on monsoon. Drought causes economic, social and environmental loss quite frequently. Management of drought needs proper storage and usage of rain and ground water in drought prone areas. Drought assessment is very important to manage water resources in lean period. It plays a vital role in managing water demands especially in agriculture sector. In the present study, monthly temperature and rainfall data for 35 years (i.e., 1985 to 2020) were collected and analysed for drought assessment. The dry spell periods were calculated using agricultural drought indices i.e. spatial rainfall on monthly basis and Soil Moisture Index.

Scaling Up Indigenous Rainwater Harvesting: A Preliminary Assessment in Rajasthan, India

Rainwater harvesting (RWH) has the potential to enhance the sustainability of ground and surface water to meet increasing water demands and constrained supplies, even under a changing climate. Since arid and semi-arid regions frequently experience highly variable spatiotemporal rainfall patterns, rural communities have developed indigenous RWH techniques to capture and store rainwater for multiple uses. However, selecting appropriate sites for RWH, especially across large regions, remains challenging since the data required to evaluate suitability using critical criteria are often lacking. This study aimed to identify the essential criteria and develop a methodology to select potential RWH sites in Rajasthan (India). We combined GIS modeling (multicriteria decision analysis) with applied remote sensing techniques as it has the potential to assess land suitability for RWH. As assessment criteria, spatial datasets relating to land use/cover, rainfall, slope, soil texture, NDVI, and drainage density were considered. Later, weights were assigned to each criterion based on their relative importance to the RWH system, evidence from published literature, local expert advice, and field visits. GIS analyses were used to create RWH suitability maps (high, moderate, and unsuited maps). The sensitivity analysis was also carried out for identified weights to check the inadequacy and inconsistency among preferences. It was estimated that 3.6%, 8.2%, and 27.3% of the study area were highly, moderately, and unsuitable, respectively, for Chauka implementation. Further, sensitivity analysis results show that LULC is highly sensitive and NDVI is the least sensitive parameter in the selected study region, which suggests that changing the weight of these parameters is more likely to decide the outcome. Overall, this study shows the applicability of the GIS-based MCDA approach for up-scaling the traditional RWH systems and its suitability in other regions with similar field conditions, where RWH offers the potential to increase water resource availability and reliability to support rural communities and livelihoods.

Combining infiltration hole and mulching techniques with fish-scale pits effectively improved soil water storage in semiarid areas with shallow buried bedrock (Pisha Sandstone) in China

Effectively regulating slope runoff and infiltrating maximum rainwater are essential to reduce soil and water loss, and promote vegetation restoration in the Pisha Sandstone areas of China, which are semiarid areas with shallow buried bedrock. However, the effects of individual or combined rainwater regulation measures, such as infiltration holes, mulch, and fish-scale pits (a semicircle-shaped pit), on soil water infiltration and restoration in such regions have not yet been fully explored. In this study, the responses of soil water to rainfall in the 0–1.6 m soil layer was investigated through in situ monitoring during the two main rainy seasons under four rainwater regulation treatments in the Pisha Sandstone area of China covered in thin soil layer (0–0.3 m): fish-scale pits with grass mulching and infiltration holes (PGH), fish-scale pits with grass mulching (PG), fish-scale pits without mulching (P), and slope land (control, CK). The results have shown that because of the relatively low permeability (0.08–0.17 m d−1) of Pisha Sandstone, individual torrential rainfall events (63.2 mm) increased the soil water only in the 0–0.3 m layer after 3 days under the CK, P, and PG treatments. However, the PGH treatment simultaneously and significantly increased the soil water in the 0–0.3 m and 0.7–0.8 m layers. Compared with the CK treatment, rainwater replenishment depths under the P, PG, and PGH treatments increased from approximately 0.4 m to 0.9 m, 1.0 m, and 1.1 m, respectively, and the average soil water storage increased by 27 mm, 34 mm, and 50 mm, respectively, in the 0–1.6 m soil layer. Moreover, the PGH treatment enhanced rainwater storage in deep soil (0.6–0.9 m), which decreased the potential for water loss by evaporation. We concluded that the PGH treatment was effective in increasing soil water storage and reducing soil erosion in areas with shallow buried bedrock.

Development of a Multi-Objective Optimal Design Approach for Combined Water Systems

Recently, due to extreme climate change, damage from flooding has been increasing; however, water shortages are being announced simultaneously. Moreover, the water distribution system’s ability to supply consumers is being overwhelmed because of urbanization, population concentration, and increases in water consumption. For this reason, to solve the water shortage problem, water reuse technologies are developing and improving that perform simple chemical treatment processes to reuse water for flushing toilets, washing, gardening, etc. but not as drinking water. However, most water reuse systems are designed and operated as independent systems, such as reusing water used in individual buildings or using rainwater. Therefore, this study develops an optimal design for the combined water systems, which is modeling and designing water distribution systems, urban drainage systems, and water reuse systems simultaneously to solve the water shortage and reduce flooding damage. To consider the combined water systems design, the existing water distribution system (WDS) demand is divided into drinking water and other uses, and the resource of other water is assumed by the rainwater storage tank for covering the amount of exceeding precipitation. To derive optimal design solutions for the combined three water systems, single- and multi-objective optimization techniques are applied considering various design criteria (i.e., construction cost, system resilience, and flooding volume on the exceeding design rainfall intensity). The developed combining water system design techniques could be used to create designs that solve the problems of medium and long-term water shortages and sustainable water systems development.

Storage, quality and use of rainwater after a "green" roof

The issue of reuse of natural resources occupies an important place in resource conservation, environmental friendliness and reduction of the man-made load of construction around the world. The use of water resources is of particular importance. They are a strategic, vitally important natural resource, the national wealth of every country, one of the natural foundations of its economic development. In addition to reasonable consumption, it is necessary to promote the preservation, restoration and reuse of water resources. One of the many methods of effective and at the same time the most natural management of water resources is "green" constructions. These are biotechnological means that combine building structures and living plants. This paper examines the implementation and creation of "green" roofs for the collection, accumulation and re-use of rainwater. The chemical composition of water after passing through the "green" roof, as well as ordinary rainwater from the roof of the building of the residential complex "Respublika" was analyzed. Water sampling was carried out in December 2021 during rainfall. It is shown that the concentration of impurities in wastewater from "green roofs" does not exceed the permissible values for drinking water. In addition, financial costs for the construction of conventional and "green" roofs were presented. Additional costs for the creation of a "green" roof will be 20.89% of the total cost of materials and 63.49% of the total cost of works for the construction of a stationary roof. Means for reuse of rainwater on "green" roofs are considered. It is shown that thanks to the retention of water by the layers of the "green" roof with an area of 490 m2, it is enough to provide a tank with a volume of 150...250 dm3. Data on the volume of used water for technical needs (irrigation) from Faina-Town residential complex in Kyiv are provided. It is shown that the accumulated rainwater is sufficient to meet the needs for watering the adjacent territory.

Modelling seasonal household variation in harvested rainwater availability: a case study in Siaya County, Kenya

Rainwater harvesting reliability, the proportion of days annually when rainwater demand is fully met, is challenging to estimate from cross-sectional household surveys that underpin international monitoring. This study investigated the use of a modelling approach that integrates household surveys with gridded precipitation data to evaluate rainwater harvesting reliability, using two local-scale household surveys in rural Siaya County, Kenya as an illustrative case study. We interviewed 234 households, administering a standard questionnaire that also identified the source of household stored drinking water. Logistic mixed effects models estimated stored rainwater availability from household and climatological variables, with random effects accounting for unobserved heterogeneity. Household rainwater availability was significantly associated with seasonality, storage capacity, and access to alternative improved water sources. Most households (95.1%) that consumed rainwater faced insufficient supply of rainwater available for potable needs throughout the year, with intermittencies during the short rains for most households with alternative improved sources. Although not significant, stored rainwater lasts longer for households whose only improved water source was rainwater (301.8 ± 40.2 days) compared to those having multiple improved sources (144.4 ± 63.7 days). Such modelling analysis could enable rainwater harvesting reliability estimation, and thereby national/international monitoring and targeted follow-up fieldwork to support rainwater harvesting.

LID 적용가능 위치 판단을 위한 중첩지도 분석

Due to climate change and rapid urbanization, most urban areas are paved, and there is insufficient space to infiltrate or store rainwater, and flood damage increases due to heavy rainfall. Research on LID techniques is being conducted to reduce the damage caused by water disasters. A systematic procedure for LID installation, quantitative scale, and facility installation in urban watersheds is required. Therefore, in this study, overlapping maps were analyzed to improve the limitations of water cycle analysis using only land cover maps in urban watersheds. Based on the overlapping map analysis, the procedure for determining the LID facility installation was presented. The peak flood volume and runoff volume were analyzed in Gimhae, Gyeongsangnam-do, using the model (XP-SWMM). As a result of the study, it was confirmed that the exact capacity of the facility can be distributed according to the target amount of water circulation by reflecting the characteristics of the basin or building information.