Intra‑District Rainfall Variability in Nashik (JJAS 2025)
Abstract
We analyze tehsil‑wise monsoon rainfall (June–September) in Nashik district as on 21 Aug 2025 from the official district bulletin. We compute mean, coefficient of variation (CV), Gini coefficient and Theil T index to quantify disparities. Results: μ=700.5 mm, s=324.5 mm, CV=0.463, Gini=0.236, Theil T=0.090. Ghat tehsils (Trimbakeshwar, Igatpuri, Peth, Surgana) are markedly wetter than plains tehsils (Malegaon, Yeola, Nandgaon).
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International Journal of Research (IJR) e-ISSN: 2348-6848 p-ISSN: 2348-795X Vol. 11 Issue 11 November 2024 Received: 2 November 2024 292 Revised: 22 November 2024 Accepted: 30 November 2024 Copyright authors 2024 DOI: HTTPS://DOI.ORG/10.5281/ZENODO.17770552 Intra‑District Rainfall Variability in Nashik (JJAS 2025) (A Quantitative Study using IMD/Nashik Tehsil‑wise Rainfall with Modern Inequality Metrics.) Dr. Yashwant K. Chaudhari Assistant Professor, Department of Commerce MVP’s Arts, Science and Commerce College, Ozar (Mig) Abstract We analyze tehsil‑wise monsoon rainfall (June–September) in Nashik district as on 21 Aug 2025 from the official district bulletin. We compute mean, coefficient of variation (CV), Gini coefficient and Theil T index to quantify disparities. Results: μ=700.5 mm, s=324.5 mm, CV=0.463, Gini=0.236, Theil T=0.090. Ghat tehsils (Trimbakeshwar, Igatpuri, Peth, Surgana) are markedly wetter than plains tehsils (Malegaon, Yeola, Nandgaon). 1. Data & 2. Methods Data. Tehsil-wise rainfall normals and percent-to-normal (June–September) are taken from the Nashik District “Rainfall Recording & Analysis” bulletin dated 21-Aug-2025; estimated actual rainfall is computed as Normal × (%/100). Methods. Let rᵢ ≥ 0 be rainfall (mm) for tehsil i, i=1..n (n=15). Mean μ, standard deviation s, coefficient of variation CV=s/μ. Inequality: (i) Gini coefficient G = 1 − 2∫₀¹ L(p) dp (L is the Lorenz curve). (ii) Theil T = (1/n)∑ (rᵢ/μ) ln(rᵢ/μ). 3. Tehsil-wise Rainfall (JJAS 2025 to-date) Tehsil Normal_JJAS_mm Pct_to_Normal_JJAS Actual_mm_est Trimbakeshwar 1601.2 96.3 1542.0 Surgana 1251.0 89.4 1118.4 Peth 1223.8 81.9 1002.3 Dindori 648.1 137.5 891.1 Chandwad 510.6 144.4 737.3 Igatpuri 1293.0 55.9 722.8 Deola 432.9 162.1 701.7 Baglan (Satana) 429.9 137.9 592.8 Nandgaon 430.3 137.7 592.5 Kalwan 469.9 108.8 511.3 Malegaon 379.0 124.8 473.0 Yeola 356.0 122.5 436.1 Sinnar 373.8 112.3 419.8 Niphad 341.8 119.8 409.5 Nashik 419.1 85.2 357.1
International Journal of Research (IJR) e-ISSN: 2348-6848 p-ISSN: 2348-795X Vol. 11 Issue 11 November 2024 Received: 2 November 2024 293 Revised: 22 November 2024 Accepted: 30 November 2024 Copyright authors 2024 DOI: HTTPS://DOI.ORG/10.5281/ZENODO.17770552 4. Results Bar chart and Lorenz curve visualizations show disparity across tehsils. 5. Short Proofs Theorem 1 (Gini bounds). For any non‑negative vector r, 0 ≤ G ≤ 1. Sketch. Lorenz curves are increasing, concave, with L(0)=0 and L(1)=1. Thus 0 ≤ ∫₀¹ L(p) dp ≤ 1/2, giving 0 ≤ G = 1 − 2∫₀¹
International Journal of Research (IJR) e-ISSN: 2348-6848 p-ISSN: 2348-795X Vol. 11 Issue 11 November 2024 Received: 2 November 2024 294 Revised: 22 November 2024 Accepted: 30 November 2024 Copyright authors 2024 DOI: HTTPS://DOI.ORG/10.5281/ZENODO.17770552 L(p) dp ≤ 1; G=0 iff all rᵢ=μ; G→1 as mass concentrates in one unit. Theorem 2 (Theil non‑negativity & decomposition). For x>0, x ln x ≥ x−1 with equality at x=1. Setting x=rᵢ/μ and averaging gives T ≥ 0 with equality iff rᵢ=μ ∀i. If tehsils are grouped by physiography, Theil T decomposes additively into within‑ and between‑group terms. 6. Interpretation Gini≈0.24 and CV≈0.46 indicate sizeable inequality. Ghat tehsils need drainage/landslide vigilance; plains tehsils need irrigation scheduling. For grapes (Niphad, Dindori) and onions (Lasalgaon cluster), wet‑spell management and storage improvements are priorities. 7. Policy Suggestions & Replication • Budget allocation: weight tehsil‑level maintenance by rainfall Theil/Gini. • Viticulture: canopy aeration, disease models triggered by 3‑day moving rainfall sums. • Onion: promote ventilated godowns and staggered curing aligned with monsoon breaks. • Replication: compute monthly inequality to monitor monsoon evolution; extend to runoff/flood reports. 8. References IMD District Rainfall Distribution bulletin (Nashik row). Nashik District Administration: 'Rainfall Recording & Analysis' (tehsil‑wise, 21‑Aug‑2025). NHB Nashik brochure (grape talukas). Agmarknet onion note (Lasalgaon market). Crop Yields (Illustrative, Nashik District) Crop Area (ha) Production (MT) Grapes 46,000 7,90,000 Onion 1,80,000 27,00,000 * * *