Integrated Approach for Identifying Suitable Sites for Rainwater Harvesting Structures for Groundwater Augmentation in Basaltic Terrain

Integrated hydrological, geophysical and groundwater modeling studies has been carried out for identification of suitable sites for rainwater harvesting structures for groundwater augmentation in RRCAT Campus, Indore, M.P. Based on these studies ten check dams, two contour bunds and one earthen bund were recommended on the existing stream channels and in valley fills respectively. Likely water impoundment on these structures was calculated keeping in view the length and width of stream channels. Based on these study a groundwater flow model using MODFLOW were carried out keeping in view the geologic and hydrologic conditions of the area. The net rechargeable impounded rain water from these structures to groundwater regime was calculated for monsoon seasons which varied from 20 % to 48 % and net enhancement of groundwater recharge from all structures would be around 0.11 mcm/year and the water level in the existing well would rise by 2–3 m above its present level for future Groundwater augmentation.     

Application of HEC-HMS Model for Evaluation of Rainwater Harvesting Potential in a Semi-arid City

Water Resources Management - With many countries facing water scarcity and the demand for water ever-increasing, more people are turning to rainwater harvesting (RWH) as a feasible way of...     

SCS-CN Based Quantification of Potential of Rooftop Catchments and Computation of ASRC for Rainwater Harvesting

Rooftop rainwater harvesting, among other options, play a central role in addressing water security and reducing impacts on the environment. The storm or annual storm runoff coefficient (RC/ASRC) play a significant role in quantification of potential of rooftop catchments for rainwater harvesting, however, these are usually selected from generic lists available in literature. This study explores methodology/procedures based on one of the most popular and versatile hydrological model, Soil Conservation Service Curve Number (SCS-CN) (SCS 1986) and its variants, i.e., Hawkins SCS-CN (HSCS-CN) model (Hawkins et al. 2001), Michel SCS-CN (MSCS-CN) model (Michel et al. Water Resour Res 41:W02011, 2005), and Storm Water Management Model-Annual Storm Runoff Coefficient (SWMM-ASRC) (Heaney et al. 1976) and compares their performance with Central Ground Board (CGWB) (CGWB 2000) approach. It has been found that for the same amount of rainfall and same rooftop catchment area, the MSCS-CN model yields highest rooftop runoff followed by SWMM-ASRC?>?HSCS-CN?>?SCS-CN?>?CGWB. However, the SCS-CN model has close resemblance with CGWB approach followed by HSCS-CN model, SWMM-ASRC, and MSCS-CN model. ASRCs were developed using these models and it was found that MSCS-CN model has the highest value of ASRC (= 0.944) followed by SWMM-ASRC approach (=0.900), HSCS-CN model (=0.830), SCS-CN model (=0.801), and CGWB approach (=0.800). The versatility of these models lies to the fact that CN values (according to rooftop catchment characteristics) would yield rooftop runoff and therefore ASRC values based on sound hydrological perception and not just on the empiricism. The models have inherent capability to incorporate the major factors responsible for runoff production from rooftop/urban, i.e., surface characteristics, initial abstraction, and antecedent dry weather period (ADWP) for the catchments and would be better a tool for quantification rather than just using empirical runoff coefficients for the purpose.     

Water Balance Approach for Rainwater Harvesting using Remote Sensing and GIS Techniques, Jammu Himalaya, India

Judicious use of the limited fresh water resources is the need of the hour. If sufficient measures are not taken up immediately, we will face a crisis which will be detrimental to the very survival of mankind. The Kandi region of Jammu district in Jammu Himalaya is facing a similar problem of acute shortage of drinking water. One of the most logical steps towards this goal would be acknowledging the importance of rainwater harvesting. The Central Ground Water Board (CGWB), North Western Himalayan Region, Jammu, has already initiated few schemes to recharge and conserve the water resources. The water resources in this study area have been estimated by water balance assessment approach. The water balance study using the Thornthwaite and Mather (TM) models with the help of remote sensing and GIS is very helpful in finding out the moisture deficit and moisture surplus for an entire watershed. The water balance calculation shows that the maximum annual runoff results from the built-up areas/water body followed by agricultural land, dense forest and minimum for the barren land and open forest. The annual deficit in the Devak–Rui watershed is 0.38 mm and the annual surplus is 1,251.34 mm. GIS software’s have been used for spatial analysis for generation of various thematic layers and integration to produce the final runoff map. The total runoff of Devak–Rui watershed was calculated as 1,160.48 mm from the total precipitation of 1,429.26 mm. It was found that suitable sites for rainwater harvesting structures in the Devak–Rui watershed covers an area of nearly 11% of the watershed area whereas the rest of the watershed area was assumed as unsuitable site for rainwater harvesting.     

Assessment of Groundwater Potential in a Semi-Arid Region of India Using Remote Sensing,GIS and MCDM Techniques

Remote sensing (RS) and geographic information system (GIS) are promising tools for efficient planning and management of vital groundwater resources, especially in data-scarce developing nations. In this study, a standard methodology is proposed to delineate groundwater potential zones using integrated RS, GIS and multi-criteria decision making (MCDM) techniques. The developed methodology is demonstrated by a case study in Udaipur district of Rajasthan, western India. Initially, ten thematic layers, viz., topographic elevation, land slope, geomorphology, geology, soil, pre- and post-monsoon groundwater depths, annual net recharge, annual rainfall, and proximity to surface water bodies were considered in this study. These thematic layers were scrutinized by principal component analysis technique to select influential layers for groundwater prospecting. Selected seven thematic layers and their features were assigned suitable weights on the Saaty’s scale according to their relative importance in groundwater occurrence. The assigned weights of the thematic layers and their features were then normalized by using AHP (analytic hierarchy process) MCDM technique and eigenvector method. Finally, the selected thematic maps were integrated by weighted linear combination method in a GIS environment to generate a groundwater potential map. Thus, four groundwater potential zones were identified and demarcated in the study area, viz., ‘good’, ‘moderate’, ‘poor’ and ‘very poor’ based on groundwater potential index values. The area falling in the ‘good’ zone is about 2,113 km² (17% of the total study area), which encompasses major portions of Sarada, Salumber, Girwa, Dhariawad, and Mavli blocks of the study area. The northeast and southwest portions along with some scattered patches fall in the ‘moderate’ zone, which encompasses an area of 3,710 km² (about 29%). The ‘poor’ zone is dominant in the study area which covers an area of 4,599 km² (36% of the total area). The western portion and parts of eastern and southeast portions of the study area are characterized as having ‘very poor’ groundwater potential, and this zone covers an area of 2,273 km² (18%). Moreover, in the ‘good’ zone, the mean annually exploitable groundwater reserve is estimated at 0.026 million cubic metres per km² (MCM/km²), whereas it is 0.024 MCM/km² in the ‘moderate’ zone, 0.018 MCM/km² in the ‘poor’ zone, and 0.013 MCM/km² in the ‘very poor’ zone. The groundwater potential map was finally verified using the well yield data of 39 pumping wells, and the result was found satisfactory.     

Development of a Simulation Model for Estimation of Potential Recharge in a Semi-arid Foothill Region

The SMPR (Soil Moisture and Potential Recharge) model is developed to simulate soil moisture content and potential recharge under semi-arid conditions. In SMPR model, infiltration and soil moisture redistribution follow two successive stages. In stage (I), precipitation infiltrates and is distributed into the soil profile utilizing the soil moisture accounting fashion and in stage (II), moisture is redistributed using simplified Richards’ equation (neglecting matric-potential gradient). Liquid and vapor evaporation from bare soil are estimated based on Dual-Crop methodology [Ke and optimized Kcb (0.17)]. Two commonly applied unsaturated hydraulic conductivity functions [K(θ)] of B-C (Brooks and Corey) and V-G (van-Genuchten); and an Empirical Exponential (E-E) equation are locally calibrated and used for potential recharge estimation (as main simulation objective). Model performance (calibration/validation) is based on reasonable estimation of potential recharge and acceptable simulation of soil moisture, considering local lysimeter data. According to results, B-C, V-G an E-E equations produced acceptable simulation of soil moisture content (NRMSE?<?30%), however, potential recharge was underestimated/overestimated, using K(θ) by B-C/V-G. The best estimation of potential recharge (based on absolute annual recharge error, ?Q?<?10%) was achieved by the SMPR model with K(θ) of E-E. Results of the relative simple SMPR model [K(θ) by E-E equation] compared favorably with HYDRUS-1D sophisticated model [using locally calibrated V-G equation of K(θ)].The proposed SMPR model requiring minimal data, can be used in regions with limited data.     

A Scenario-Driven Assessment of the Economic Feasibility of Rainwater Harvesting Using Optimized Storage

Water Resources Management - Regional water scarcity has given rise to the search for sustainable means of water supply. Rainwater harvesting (RWH) has been receiving unprecedented attention as...     

Estimation the Physical Variables of Rainwater Harvesting System Using Integrated GIS-Based Remote Sensing Approach

Water Resources Management - Geographic Information System (GIS) are an intelligence technique skilled to extract, store, manage and display the spatial information for various applications of...     

雨水集蓄灌溉技术在石灰岩地区的应用

大量的实践证明，在农作物缺水的关键时期进行补充灌溉，用很少的水量，就可以发挥很大的作用。针对石灰岩地区干旱缺水的情况，详述了雨水集蓄灌溉技术，并阐明了通过些技术可以改善石灰岩地区的农业生产条件，促进当地农业可持续发展。     

A New Model for Simulating Supplemental Irrigation and the Hydro-Economic Potential of a Rainwater Harvesting System in Humid Subtropical Climates

Here we have developed a new model to simulate supplemental irrigation and the hydro-economic potential of a rainwater harvesting system in rainfed agricultural areas. Using the model, soil moisture in rainfed crop land, supplemental irrigation requirements, rainwater storage in an on-farm reservoir (OFR) system, and surface and ground water availability were predicted. In an irrigated system, an OFR was used to harvest rainwater during the rainy season, and stored water was applied to cropland as supplemental irrigation (SI). An economic analysis was performed to calculate the benefits due to an OFR irrigation system, and gains from increased crop yield and downstream water availability in the irrigated OFR system were compared with rainfed system (i.e. no OFR). In addition, we calculated the impacts of dry and wet seasons on total value gains (grain and water gains) for irrigated and rainfed conditions and performed a sensitivity analysis to quantify the impacts of model input parameters on total value gains. Analyses showed that the OFR system can produce crop yields three times greater than rainfed agriculture. During a water stress season, the total water use in the irrigated system was 65 % greater than for the rainfed system. Water use efficiency of the irrigated system was 82 % higher than for the rainfed system. In a dry season, the total value gains due to increased crop yield by supplemental irrigation and downstream water availability of the irrigated system were 74 % greater than for the rainfed system, while in a wet season the total value gain of the irrigated system was 14 % greater than for the rainfed system. A precipitation scenario analysis of wet and dry seasons indicated that the benefits of a rainwater harvesting system can be considerably greater in dry seasons than wet seasons.     

Planning and Design of Cost-effective Water Harvesting Structures for Efficient Utilization of Scarce Water Resources in Semi-arid Regions of Rajasthan,India

Water-harvesting structures have the potential to increase the productivity of arable lands by enhancing crop yields and by reducingthe risk of crop failure in arid and semi-arid regions, where water shortages are common because of scanty rainfall and its uneven distribution. In semi-arid regions of Rajasthan, India, existing practice of harvesting rainwater is through anicut and earthen embankments. Because of higher costs and higher technical skills involved in the construction of these structures, these structures have not been accepted by the resource-poor local people. Therefore, in the present paper, the detailed design of some low-cost water-harvesting structures using locally available materials and adaptable to the socio-economic conditions of the beneficiaries is discussed. Two types of cost-effective water-harvesting structures, which include dry stone masonry and upstream-wall cement masonry of heights 1, 2, and 2.5 m for catchments of less than 10, 10 to 20, and 20 to 30 ha, respectively are proposed and designed. The analysis of costs involved in constructing dry stone masonry and upstream-wall cement masonry water-harvesting structures, emergency spillway, anicuts and earthen embankments revealed that the earthen embankments have the least cost of construction whereas the anicuts have the highest construction costs for all the selected heights. However, based on the past experiences, earthen embankments are not suitable for the semi-arid regions of Rajasthan. The economic evaluation of the proposed structures indicated that the dry stone masonry structures are very cost-effective for the region with a benefit-cost ratio of 3.5:1 and the net present worth value of Rs. 102978. Although the economic indicators ranked the upstream-wall cement masonry structures lower than the dry stone masonry structures, the former has greater stability and strength compared to the latter. In practice, both the cost-effective water-harvesting structures (i.e., dry stone masonry and upstream-wall cement masonry) are gaining wide acceptance and popularity in the region through some nongovernmental organizations, which have adopted the design presented in this paper.     

Preliminary Assessment of Rainwater Harvesting Potential in Nigeria: Focus on Flood Mitigation and Domestic Water Supply

This study was accomplished using 26 locations in the major ecological zones of Nigeria as well as different classes of residential buildings and different levels of water consumption. For each location, house dwelling class and level of water consumption, a water balance approach was used to assess the proportion of water demand that can be met by rainwater. Results obtained indicate that for all the locations in the rainforest zone and some parts in the guinea savanna zone, over eighty percent (80 %) of water demand of those living in bungalows can be met by rainwater. Rainwater harvesting potential was found to be a power function of rainfall coefficient of variation, with coefficient α and exponent β. High correlation coefficients (0.881?≤?R ² ?≤?1) were obtained between coefficient α and roof area per capita. Also, high correlation coefficients (0.847?≤?R ² ?≤?0.992) were obtained between exponent β and roof area per capita.     

Effectiveness of Rainwater Harvesting in Runoff Volume Reduction in a Planned Industrial Park,China

It is urgent to effectively mitigate flood disasters in humid mountainous areas in southeastern China for the increasing flood risk under urbanization and industrialization. In this study, a rural district with an area of 13.39 km² that planning to build an industrial park covering an area of 7.98 km² in Changting was selected to estimate the potential of collectable rainwater and the extent to which runoff volume can potentially be mitigated by rainwater harvesting. In addition, the optimum cistern capacity of a rainwater harvesting system in the planned industrial park was evaluated using daily water balance simulation and cost-efficiency analysis. The results showed that rainwater harvesting in the planned industrial park has great potential. The annually collectable rainwater is approximately 9.8?×?10⁶ m³ and the optimum cistern capacity is determined to be 0.9?×?10⁶ m³. With the optimum cistern capacity, the annual rainwater usage rate is 0.99, showing neither financial savings nor deficits. Rainwater harvesting can reduce 100 % of runoff volume in the cases of critical rainfall storm (50 mm) and annual average maximum daily rainfall (111.2 mm), and 58 % of runoff volume in the case of maximum daily rainfall (233.6 mm), respectively. All surface runoff can be collected and stored in the cisterns when rainfall amount is less than 135.5 mm in a rainstorm event.     

辽西半干旱区玉米微喷带灌溉试验研究

微喷带是适宜辽宁西部地区补充灌溉的节水灌溉技术,为了提高微喷带的适用性,文章通过与滴灌(DI)和漫灌(FI)做对比试验研究了玉米微喷带灌溉(SI)的效果。试验结果表明SI较FI节水35%,灌溉次数为DI处理的1/2;SI和DI较FI对植株营养生长有一定抑制作用,但均促进了生殖生长,获得较多的穗行数和行粒数;SI节水增产效果低于DI,仍较FI玉米产量和WUE分别提高1.1%和19.0%。因此,微喷带灌溉可用于玉米节水灌溉,尤其在滴灌等设备使用效率低的补充灌溉地区,微喷带是适宜的选择。     

Correction to: A Scenario-Driven Assessment of the Economic Feasibility of Rainwater Harvesting Using Optimized Storage

Water Resources Management - Unfortunately the original version of this article contains a mistake. The correct Fig. 1 is shown here.     

Development of a Rainfall-Recharge Relationship for a Fractured Basaltic Aquifer in Central India

Groundwater being an important component of the hydrological cycle, estimation of its annual replenishment is essential to evolve a plan for optimum utilization. Groundwater balance approach, which is used extensively for the quantification of recharge and discharge components has been adopted for the rainfall-recharge estimation. Various inflow and outflow components have been identified and estimated for Sagar block in Sagar district of Madhya Pradesh, which faces acute water scarcity and continuous decline in groundwater levels. The computed recharge from rainfall varies between 122.45 and 183.71 MCM. The computed rainfall-recharge is compared with the Chaturvedi (1973), Kumar and Seethapathi (2002), Krishna (1987), and U.P. Irrigation Research Institute models. Models have also been developed to estimate rainfall-recharge for varying ranges of the annual rainfall and have been compared with the existing models. The relative error in estimation of rainfall-recharge from proposed models varies between 0.03 and 9.24%. The overall scenario is net decline in groundwater storage to an extent of ?31.31 MCM over a period of 16 years from 1985–1986 to 2000–2001. The trend analysis by Kendall’s rank correlation test, regression test for linear trend and Mann–Kendall test also clearly suggests falling trends in groundwater storage at 5% significant level, thereby demonstrating over-exploitation of the groundwater aquifer. This has subsequently led to progressive decline in groundwater table in the study area. Efforts should be initiated to tap the surface water by creating storages at suitable sites and artificial recharge practices should be encouraged after identifying suitable recharge zones. Conjunctive use of the surface and groundwater along with water conservation practices and groundwater management measures should be taken up to arrest the progressive decline in groundwater levels and over-exploitation of groundwater aquifer.     

集雨工程 服务民生 创新机制 促进发展——昔阳县雨水集蓄利用工程建设经验和体会

<正>昔阳县位于山西省东部,十年九旱、十年十灾的气候条件造就了其干旱缺水、水资源奇缺的特征。因缺水,许多村必须到几十里外拉水;因缺水,严重束缚了劳动力的再生产;因缺水,直接制约着人民生活水平的提高和社会经济的发展。水问题已成为昔阳县经济发展的桎梏。只有发展水利,才能摆脱干旱对     

Modeling the Effect of Cistern Size,Soil Type,and Irrigation Scheduling on Rainwater Harvesting as a Stormwater Control Measure

Urban stormwater runoff could have negative impacts on water resources and the environment. Rainwater Harvesting (RWH) can serve both as a stormwater control and water conservation measure. Cistern size and irrigation scheduling are two of the factors that directly impact the total runoff from a residential unit with a RWH system and the amount of potable water used for irrigation. The effectiveness of RWH was evaluated for four soil types; Sand, Sandy Loam, Loamy Sand, and Silty Clay, with a root zone of 15.2 cm using three irrigation scheduling methods (Evapotranspiration (ET)-based, soil moisture-based, and time-based), and five cistern sizes. Total runoff volumes and total supplemental potable water used were compared among the three irrigation scheduling systems and a control treatment without RWH. A model was developed to simulate the daily water balance for the treatments. Irrigation and runoff volumes were compared for the various scenarios. Silty clay soil resulted with 83 % more runoff than Sandy soil, while Sandy soil required on average 58 % more supplemental water than Silty Clay soil. On average, the 833 L cistern resulted with 41 % savings in water supply and 45 % reduction in total runoff. Results showed that the greatest volumes of runoff predicted were for the silty clay soil Control Treatment using a time-based irrigation scheduling method, while the least volumes calculated were for the sandy loam soil time-based irrigation scheduling treatment with 833 L cistern size. The greatest volumes of total supplemental water predicted were for sandy loam soil Control Treatment, while the least volumes were for silty clay soil ET-based irrigation scheduling treatment with 833 L cistern size. Regression equations were developed to allow for users to select a RWH cistern size based on the amount of water they want to save or runoff to reduce.     

Identification of Potential Sites for Groundwater Recharge Using a GIS-Based Decision Support System in Jazan Region-Saudi Arabia

In arid and semi-arid environments, the amount of recharge received by aquifers is far more critical to the sustainable use of water than it is in humid regions. Groundwater recharge (GWR) is critical to maintain the abundance of groundwater. In the present study, suitable areas for GWR in Jazan region have been identified by using a GIS-based decision support system (DSS). The DSS was implemented to obtain suitability maps and to evaluate the existing GWR in the study area. The DSS inputs comprised maps of rainfall surplus, slope, potential runoff coefficient, land cover/use and soil texture. The spatial extents of GWR suitability areas were identified by a hierarchical process analysis that considered five layers. The model generated a GWR map with four categories of suitability: excellent, good, moderate and poor and unsuitable. The spatial distribution of these categories showed that 50.5 and 31 % of the study area was classified as excellent and good for GWR, respectively, while 16 and 2.5 % of the area were classified as moderate and poor and unsuitable, respectively. Most of the areas with excellent to good suitability have slopes of between 4 and 8 % and are intensively cultivated areas. The major soil type in the excellent to good areas is loamy sand, followed by silt loam, and the rainfall in these areas ranges from 100 to 270 mm. The locations of existing GWR dams were compared with the locations indicated on the generated suitability map using the proximity analysis tool in ArcGIS 10.1. Most (75 %) of the existing GWR structures that were categorised as successful were within the excellent and good areas, followed by moderately suitable (25 %).     

Improvement of Rainwater Harvesting Analysis Through an Hourly Timestep Model in Comparison with a Daily Timestep Model

Water Resources Management - For the analysis of rainwater tank outcomes, some researchers used monthly water balance model, which ignores an important factor such as overflow from the tank....