Development Of Drought Risk Map Of Zayandehrud Dam Catchment Using Water Resource Approach Process

Tujuan utama kajian ini adalah untuk menambahbaik metodologi untuk menilai tren kemarau dan memahami kaedah yang sesuai, bergantung kepada keadaan sebenar kawasan tadahan untuk mengurangkan impak kemarau. Sebanyak 15 stesen meterologi dan 9 tolok aliran air di sekitar Tadahan Empangan Zayandehrud (ZDC), di tengah Iran telah pilih untuk dianalisa. Rangka kerja yang dipilih untuk kajian ini ialah model Proses Pendekatan Sumber Air (WRAP), satu teknik hybrid, data geologi dan morfometri di gunakan untuk lebih memahami impak dan tren kekurangan air. Penilaian index kemarau meteorologi sedia ada, iaitu Indeks Hujan Piawai (SPI), Indeks Skor Z (ZSI) dan Desil telah gunakan untuk menilai kesesuaian penentuan keadaan kemarau. Penggunaan Indeks Hujan Piawai (SPI) didapati sesuai untuk menilai kemarau meteorologi di Iran. SPI juga sesuai untuk mengenalpasti titik permulaan dan tamat sejarah kemarau. Untuk menganalisa aliran, Indeks Aliran Piawai di gunakan. Beberapa plot serak dan rajah lengkung SPI dan SSFI nenunjukkan keputusan yang berkait rapat. Penilaian hujan, ujian, Mann–Kendall (MK), cerun Sene dan ujian LOWESS digunakan untuk menganggar signifikan tren temporal kedua-dua hujan dan aliran. Satu proses parametrik separa dan parametrik berkaitan dengan kaedah anggaran bergerak berintegrasi autoregresi pecahan dan ujian penskalaan MK digunakan untuk menilai signifikan tren temporal. Keputusan kajin untuk majoriti aliran siri masa berbanding hujan dalam masa kemarau menunjukkan tren selari, menunjukkan majoriti air larian pada masa susulan yang pendek dan kurang aliran penyusupan ke hilir. Kebanyakan stesen hujan dan tolok aliran menunjukkan tren meningkat. Perubahan yang tinggi berlaku di sebelah barat kawasan kajian. Di utara dan timur laut didepati tren peningkatan yang be kurangan, oleh kerana kesan penyejatan empangan. Masalah besar di kawasan pergunungan ialah kekurangan akuifer yang sesuai, oleh itu struktur geologi dan system stratigrafi memainkan peranan untuk sumber air. Di bahagian tengah dan timur-laut ZDC terdapat akuifer yang mencukupi tetapi hujan yang rendah dan tekanan tinggi pada air bumi menghasilkan ambeles dan degradasi tanah. Peta kerentanan dan risiko telah dihasilkan dengan mengintegrasi peta asas dengan data peta kemarau dan iklim, peta geologi, data morfometrik dan peta hakisan. ________________________________________________________________________________________________________________________ The overall goal of this study is to improve a methodology to appraise drought trends and understanding of appropriate way, rely on the real condition catchment area, to reduce drought impacts. A total of 15 meteorological stations and 9 streamflow gauges across Zayandehrud Dam Catchment (ZDC), central of Iran were selected for analysis. Furthermore, as selected framework of this investigation make use Water Resources Approach Process model (WRAP), which is a hybrid technique, geological and morphometric data were used to better understanding impacts and trends of water scarcity. An assessment of existing meteorological drought indices namely, the Standardised Precipitation Index (SPI), the Z-Score Index (ZSI) and Deciles was first conducted to assess their suitability for the determination of drought conditions. The use of the Standardised Precipitation Index (SPI) was found to be suitable for analysing meteorological droughts in Iran. SPI was also operative in identifying the onset and the end of historical droughts. For analysing streamflow the Standardised Streamflow Index (SSFI) was used. Several scatter plot and curve diagrams of SPI and SSFI were shown to be closely correlated. Mann–Kendall (MK) test, Sen’s slope and LOWESS test were used to estimate significance of temporal trends in both precipitation and streamflows. A semiparametric and a parametric process associated with the fractional autoregressive integrated moving average modelling approach and a MK scaling test are employed to assess significance of temporal trends. The results of the study propose that for the majority of the time series of streamflows in contrast to precipitation in drought duration shows parallel trends, which indicates that majority of runoff in short lag time and in less infiltration flows to downstream. Majority of rain stations and streamflow gauges shown downward trends. Highest variations occurred in western part of case study area. In north and north-east a weak upward trends was detected, this is due to influence of dam evaporation. Major problem of mountainous area is lack of reasonable aquifer, so geological structures and stratigraphical systems provides the main groundwater holder. On the other hand central and north-eastern part of ZDC contained significant aquifers but low precipitation and high stress on groundwater resulted from subsidence and land degradations. Vulnerability and risk map were developed by integrating basic maps with i.e. drought and climatic maps, geological map, morphometric data and erosion map