امکان‌سنجی استحصال آب باران از حوضه‌های آبخیز پشت‌بامی در مناطق روستایی (مطالعه‌ی موردی: بخش رضویه، شهرستان مشهد)

Introduction
Climate changes, lack of atmospheric precipitation, increasing of world population, and in result, increasing the environmental pollutions in the face of relevantly fixed and nonincreasable renewable water sources concerned governors and experts in water issues. Geographically, Iran is located at the dry and semidry regions of the world in a way that, it has almost dry weather with little rain and snow, except at the Caspian Sea border and altitudes of Alborz and Zagros. It has also a limited water resources on the world average. The average raining is 250mm in a year, less than one third of world average raining, and the evaporation average is almost 3 of the world average.Frequent draught in our country has caused many economic and social problems for the rural society. The important part of gardens and farms which have benefitted from water sources such as spring, duct, rivers and seasonal rains, have been now deserted and have lost their capacity to cultivation in water method. Water shortage has made the economic activities difficult for the rurals and has destroyed part of their income sources. In result, the rurals inevitably leave their home and immigrate to big cities working in order to earn. Considering aridity crisis in Iran, knowing and using the newest scientific and technical methods, inspired by traditional methods, is necessary for decreasing the crisis of draught. One of the main methods which can be effective with the minimum time and cost for providing money in the rural areas, with the simple technology, is extracting rain water from rooftop basin aquifer. Employing this system will be practical in any time, any place, without any topographical geology limitation and with gathering rain water, it provides part of water supply of the rurals for home uses such as:hygienic, service, cleaning uses, cooking, feeding poultry and livestock. The history of extracting rain water systems dated back to the thousands of years B.C. and past civilizations have been using this water for drinking, irrigation and home uses. Supported by native knowledge, good researches have been done globally in the field of extracting rain water, but the studies in Iran are few. Furthermore, most of these studies have been done for more than one year, focusing on improving the moisture of soil for agriculture.Benefitting from the previous studies, this research attempts to study the effect of this system in a minimum time by measuring the possibility of rural water use by basin aquifers of rooftop with the purpose of resolving the problem of water supply to rural areas. This research has been done at Razaviyeh division, Mashhad, Khorasan Razavi. Razaviyeh division has been founded on 1991 and it is one the quarterly divisions of Mashhad, having three rural districts: Mayamey, Abravan, and Payin Velayat, admeasuring 387, 65 square kilometre. According to Iran Census Center, the population of Razaviyeh district has reached 50169 people (in 13566 families) in 2016.
 
 
Materials and Methods
This study is practical in purpose, descriptive and analytical in essence and methodology. For gathering information, two methods of fieldwork and non- fieldwork and fixing sample volume using Cochran formula, equivalent to 251 persons. The main tool is questionnaire, with total 28 questionnaires, which has been distributed among the rurals systematically by chance, and then the information was gathered. Sample villages under study include 6 villages selected out of 57 villages of over 20 families. Research Hypothesis: 1- the rurals cooperate with the project of gathering rain water from rooftop basin aquifer 2- The rural residences are compatible with gathering rain water from rooftop basin aquifer project. Data analysis (considering the type of research, hypotheses and collecting information methods) is done in descriptive and deductive graph, and descriptive statistical techniques including abundance figure were used for analyzing the demographics data of statistical sample.
Discussion and Results
Analyzing the probability of gathering rain water by rooftop basin aquifer in the division under study showed that not only the rurals are highly motivated to cooperate in performing this project, but also they understand the importance and operation of this project as a useful and low costs method for controlling the water shortage crisis and decreasing the support to the concentrated water supply systems to the remote places such as pipe water, dam, well, subterranean canal, water supply tank, and reviving stable level? Due to needing the water, they are looking for developing and combining the traditional methods of using rain water with today’s knowledge and they use every drop of rain for their life. They need local and private organizations’ help and support in resolving the problems, especially depreciated building of the village and helping to buy the project’s primary necessary equipment. Therefore, reviving some of forgotten methods is inevitable, and its performance need governmental and private financial supports, doing basic and practical research, and also knowing and evaluating them closely.
Conclusions
Iran is one of the countries which has the most water shortage, but cultural systems of such has not been used wildly yet. Although, using rain water gathering methods depends on whether condition meaning the raining, and usually is not used in small scales, all in all, it is very important and useful for places with little raining and not enough water for production and those where fresh water is not available. Using extraction system of rain water from rooftop basin aquifer at the raining times, provides part of families’ water needs. In addition to satisfying and supplying water in time of pipe water cutoff, it saves time and money. Avoiding flood-water, gathering rain water from rooftop can help preserving environment and protecting soil and water, and also decreases the transferring and spreading superficial pollution. Since in the technology of extracting rain water from rooftop as a domestic system, the rurals themselves as the main owners protect and control it without needing other members society, and it is almost flexible and compatible with vast spectrum of conditions and it can be used in rich and poor societies, in all places, without topographical and geological limitations, optimizing native systems and resolving its probable defects with education, persuasion, promoting and presenting  technical and financial help to the users are suggested.